EU4 - Development Diary - 19th of October 2021

[Ogele]

Hello and welcome to the 5th Dev Diary for the upcoming Africa update!

Today we shall take a look at the two biggest tags in East Africa and Southern Africa: Kilwa and Mutapa as well as the formables of Africa. Please take into account that all modifiers and numbers are currently under ongoing testing, and as we want to continue gathering your feedback, some may be changed before release. Let’s get started with Kilwa!

Kilwa has been historically a great trade power in East Africa with connections to Far East Asia. To represent this, the mission tree is heavily focused on the naval presence and trade dominance of the trade nodes which eventually lead into the Zanzibar trade node.

The first column from the left focuses on the gold sources of Mutapa as well as the colonization of Southern Africa. “The Gold of Zimbabwe” will give you access to a decent conquistador, which allows you to explore the Cape, while the mission “The Uncharted South” grants you a colonist for 30 years to make life a little bit easier.

The second column is more focused on the development of your heartland while the third column revolves around the conquest of the coastline of the Zanzibar trade node and African coasts of the Gulf of Aden coastline. Your final goal, “Claim Trade Hegemony”, is to funnel the trade flow to your home trade node and to secure it. By doing so you will get a neat +15% Trade Efficiency for the rest of the game.

Finally, the fourth and fifth columns are about dominating the trade of Malacca and the Moluccas. Although these missions give you a bonus to colonization, it is possible to complete these missions through trading alone. It is not absolutely required to colonize - with the exception of the Australia mission.

Now, there is one mission I want to highlight more, which stands out on its own: “Reconnect with Persia”. According to Kilwan legends, the sultanate was founded by one of the seven sons of the Persian Emir Al-Hassan of Shiraz. While the historical base of the legend is questionable, it served as the legitimation of the ruling dynasty of Kilwa. The mission goes a step further and allows Kilwa to establish contact with the home land they believe to originate from.

You can complete the mission through either allying with the owner of the province Shiraz or by having one regiment positioned in the province of Shiraz (without being at war with the owner) - how you achieve this is up to you. Completing the mission will trigger the following event:

Of course the owner of Shiraz will receive a contact event from Kilwa too:

While the embassies are a nice passive bonus, they also provide some useful events for both countries from time to time. There are 3 random events in total, which are the following:

All three random events share a hard cooldown of 10 years and have a mean time to happen of 5 years.
Additionally there are two events for Kilwa, which happen a lot more rarely:

I also should point out that if either nation loses the embassy, the other country will lose their own too, severing the diplomatic connection both had.

Additionally to the mission tree, Kilwa received its own set of ideas too!

Spoiler: Kilwa Ideas

ZAN_ideas = {
    start = {
        naval_forcelimit_modifier = 0.25
        global_ship_trade_power = 0.2
    }
 
    bonus = {
        global_trade_power = 0.1
    }
 
    trigger = {
        tag = ZAN
    }
    free = yes
 
    zan_kilwa_latitude_staves = {
        trade_range_modifier = 0.25
        range = 0.2
    }
 
    zan_shirazis_legacy = {
        legitimacy = 1
    }
 
    zan_the_deal_with_almuli = {
        diplomatic_reputation = 1
        trade_company_investment_cost = -0.1
    }
 
    zan_kilwa_the_melting_pot = {
        idea_cost = -0.05
    }
 
    zan_gold_of_sofala = {
        monthly_gold_inflation_modifier = -0.2
        inflation_reduction = 0.03
    }
 
    zan_trade_center_of_zanzibar = {
        merchants = 1
    }
 
    zan_center_of_migration = {
        development_cost = -0.1
    }
}

With that said, let us move on to Mutapa!

Mutapa is the successor state of Zimbabwe, and as such your mission tree revolves around surpassing this realm of old times. As Mutapa you also start with your capital Zimbabwe, which declines rapidly shortly after game start:

The third column of the mission tree is focusing on restoring the once great city and to bring it back to its former glory. “Fate of Zimbabwe” helps fortunately out as it has a very unique reward, which is the ability to increase development through constructing buildings.

The development from the buildings you get harmonizes with the modifier of the building. So in other words you get the following development for constructing the following buildings:

• Trade Buildings increase Local Production by 1/2/3
• Navy Buildings increase Local Production by 1/2
• Army Buildings increase Local Manpower by 1/2
• Production Buildings increase Local Production by 1/2
• Government Buildings increase Local Tax by 1/2
• Taxation Buildings increase Local Tax by 1/2
• Universities increase Local Tax by 2
• All manufactory buildings except for the Ramparts, State House and Soldier’s Households increase Local Development by 2
• State Houses increase the Local Tax by 2
• Soldier’s Households increase the local manpower by 2

I want to point out that upgrading a building will also add development to a lesser degree. For example: if you build a cathedral you gain +2 Local Tax. If you upgrade a church, which already gave you +1 Local Tax, to a cathedral you gain again +1 Local Tax.

This way you have a little bit of an easier time in achieving the mission “Restore Zimbabwe”, which requires you to have 20 development in the Zimbabwe province again. As a reward the “Abandoned Ruins” province modifier gets removed and the local development cost is reduced by 15% for the rest of the game. It also gives +0.5 legitimacy too.

Reaching 400 development and reaching the borders of old Zimbabwe will allow you to complete the mission “Eclipse Great Zimbabwe”, granting you the Empire rank and firing the following event for you:

(The borders you see on the image are not required to have to form Zimbabwe)

Spoiler: Zimbabwe Ideas

GZI_ideas = {
    start = {
        fort_maintenance_modifier = -0.1
        land_morale = 0.15
    }
 
    bonus = {
        trade_efficiency = 0.2
    }
 
    trigger = {
        tag = GZI
    }
    free = yes
 
    gzi_stone_masonry = {
        build_cost = -0.15
        great_project_upgrade_cost = -0.1
    }
    gzi_ivory_trade = {
        global_trade_goods_size_modifier = 0.1
    }
    gzi_gold_deposits = {
        global_tax_modifier = 0.1
        monthly_gold_inflation_modifier = -0.2
    }
    gzi_zimbabwes_walls = {
        defensiveness = 0.25
    }
    gzi_lay_of_the_land = {
        hostile_attrition = 1
    }
    gzi_tributary_system = {
        vassal_income = 0.2
    }
    gzi_zimbabwe_birds = {
        production_efficiency = 0.15
    }
}

While the third column of missions revolves around Zimbabwe, the first one is more about the internal, religious stability of Mutapa. The second column is about getting Southern Africa under your control and becoming one of the great powers. “Great Power of Africa” especially emphasizes it as you are required to be amongst the top three great powers (or have 700 total development if Rights of Man or Emperor is not active) and have an army size of 100 regiments. As a reward you gain +25 Permanent Power Projection.

The fourth column of missions is very similar to the Kilwan trade missions. However, it focuses more on getting access to the trade node of China instead of dominating it.

Finally we have the last column on the most right, which is about overhauling your military - and recruiting the Nguni for your army. “Recruit the Nguni” especially will be interesting for the people who want to tag switch into a strong, military country while still having a challenge to face. For that you must reach administrative tech 15 (which is the “Military Administration” technology) and develop the manpower of Mtetwa and Natal to 8 for both of them. After that you get this lovely event:

The Zulu are intended to be a fun country to play, even if we know that they may spawn this way much earlier than in our timeline. Because of that we have abstained from creating a mission tree for them. However, because the Zulu here are directly created through militarization of the Nguni, the ideas are heavily inspired by the reforms of Shaka Zulu:

Spoiler: Zulu Ideas

ZUL_ideas = {
    start = {
        army_tradition_from_battle = 1
        land_forcelimit_modifier = 0.25
    }
 
    bonus = {
        discipline = 0.05
    }
 
    trigger = {
        tag = ZUL
    }
    free = yes
 
    zul_confederacy_of_clans = {
        stability_cost_modifier = -0.1
    }
    zul_the_ukubuthwa = {
        manpower_recovery_speed = 0.2
    }
    zul_the_impi_warriors = {
        infantry_power = 0.1
        shock_damage = 0.1
    }
    zul_zulu_expansion = {
        core_creation = -0.1
        years_of_nationalism = -3
    }
    zul_warrior_culture = {
        land_morale = 0.15
    }
    zul_shaka_reforms = {
        reform_progress_growth = 0.1
        governing_capacity_modifier = 0.1
    }
    zul_conquest_through_patronage = {
        accept_vassalization_reasons = 10
    }
}

Also, you don’t have to start as Mutapa to create the Zulu. Every country with their capital in Southern Africa has the decision “Militarize the Nguni”, which has the same requirement as the Mutapa mission. The big difference however is that you don’t fire an event immediately. Instead you gain 2 years worth of manpower and increase the unrest in your two Nguni provinces by 5 for 25 years. Additionally, the following event can fire:

It should be noted that the AI will NOT attempt to enact the decision. The “Rise of the Zulu” event can fire naturally when the year is 1750 or later and is guaranteed to fire around 1816.

Speaking of formables: we introduce a bunch of formable countries with patch 1.32 in Africa (and one in the Middle East). Here is a little gallery of what you can expect!

Spoiler: Kitara Ideas

KIT_ideas = {
    start = {
        infantry_power = 0.1
        manpower_recovery_speed = 0.15
    }
 
    bonus = {
        stability_cost_modifier = -0.15
    }
 
    trigger = {
        tag = KIT
    }
    free = yes
 
    kit_legacy_of_the_gods = {
        legitimacy = 1
        tolerance_own = 2
    }
    kit_empire_of_the_light = {
        prestige = 1
    }
    kit_memory_of_aksum = {
        embracement_cost = -0.2
    }
    kit_lakes_dominance = {
        discipline = 0.05
    }
    kit_bachwezi_earthworks = {
        build_cost = -0.1
    }
    kit_nile_conquest = {
        core_creation = -0.15
    }
    kit_rich_history = {
        culture_conversion_cost = -0.25
    }
}

Spoiler: Nubia's Ideas

NBI_ideas = {
    start = {
        land_morale = 0.15
        hostile_attrition = 1
    }
 
    bonus = {
        prestige = 1
    }
 
    trigger = {
        tag = NBI
    }
    free = yes
 
    nbi_our_land = {
        global_unrest = -2
        stability_cost_modifier = -0.15
    }
 
    nbi_religious_friction = {
        global_missionary_strength = 0.02
    }
 
    nbi_desert_knowledge = {
        land_attrition = -0.1
    }
 
    nbi_military_strength = {
        discipline = 0.05
    }
 
    nbi_nile_control = {
        trade_efficiency = 0.1
        production_efficiency = 0.1
    }
 
    nbi_christian_ties = {
        tolerance_own = 2
    }
 
    nbi_egyptian_relations = {
        adm_tech_cost_modifier = -0.1
    }
}

Spoiler: Aksum's Ideas

AKS_ideas = {
    start = {
        prestige_decay = -0.01
        land_morale = 0.15
    }
 
    bonus = {
        global_manpower_modifier = 0.33
    }
 
    trigger = {
        tag = AKS
    }
    free = yes
 
    aks_stellae_builders = {
        prestige = 1
    }
 
    aks_legacy_of_king_kaleb = {
        ae_impact = -0.15
    }
 
    aks_persian_revenge = {
        province_warscore_cost = -0.25
    }
 
    aks_christianity_stronghold = {
        tolerance_own = 2
    }
 
    aks_mediterranean_contacts = {
        technology_cost = -0.1
    }
 
    aks_trade_hub = {
        trade_efficiency = 0.15
    }
 
    aks_coin_minting = {
        inflation_reduction = 0.1
    }
}

@Pavía already announced that Judaism gets new mechanics. Because of that we have decided to give one more addition for Jewish countries, which is the formable country of Israel!

Spoiler: Israel's Ideas

ISR_ideas = {
    start = {
        legitimacy = 1
        religious_unity = 0.25
    }
 
    bonus = {
        diplomatic_reputation = 1
    }
 
    trigger = {
        tag = ISR
    }
    free = yes
 
    end_of_diaspora = {
        global_unrest = -1
        church_power_modifier = 0.15
    }
    national_myths_restored = {
        discipline = 0.05
    }
    return_home = {
        production_efficiency = 0.2
    }
    jewish_trade_tradition = {
        trade_efficiency = 0.1
        trade_steering = 0.1
    }
    pious_people = {
        tolerance_own = 2
    }
    people_of_exile = {
        development_cost = -0.1
    }
    the_chosen_people = {
        land_morale = 0.1
    }
}

As Butua you can form Rozwi, but your ideas will not change. It is basically a color and flag change and a free kingdom rank for you.

Of course we also have these two as formables now!

Additionally, the decision to form Sokoto has been improved too, allowing you to form them earlier - if you achieve the requirements of course.

One last point I want to address: in my last dev diary I mentioned that Fetishism receives some buffs. I also presented the idea of Cults for your heirs. While this mechanic is a mission tree reward for Kongo, it is actually available for every Fetishist country in the world - but in a different form. With 1.32 we introduce a bunch of new estate privileges, which you can use to improve your experience. Here is a small list of the new privileges we have for you:

These privileges are part of “Rights of Man”.
“Embrace Singular Cult” improves the modifier of the cult you have active by 100%.
“Embrace Singular Cult” cannot be active with “Build Shrines for Heirs” and “Flexible Cults” at the same time.
We also have two new privileges for Muslim countries:

These privileges are part of “Cradle of Civilization”.

We also have privileges which are part of the free update for you to use!

Values are all subjects to changes of course. I would like to hear your personal first impression and feedback about the privileges so we can release them in a more balanced state!

With that said, I hope you enjoyed this dev diary! @Pavía will continue with an overview of the remaining mission trees and the mechanics for Judaism. Until then I wish you a nice week!

 

[Ogele]

Hooray for new formables!

The Establish Religious Schools privilege effect sounds a bit odd though. "Inviting a scholar no longer costs" or "does not cost" sound better. "does no longer cost" just sounds weird.

The +30% influence for a bunch of the new privileges seems a bit much too. Considering you need more loyalty than influence to remove them, and those privileges don't give any loyalty (and few if any give more loyalty than they do influence), taking one of those would make removing any privileges for that estate difficult.

Both problems are on me. The art of writing tooltips is one I have yet to master properly.
For the +30% influence issue: I was very conservative with the balancing of the privileges because I was not entirely sure how strong these effects are in the game. I am still testing the impact these privileges have.
But for what I can tell, I think I will reduce them to ~15% influence (+/- 5%)

This embassy event release is a great moment to emphasize that Persia almost never forms by itself, unless the developers did something without announcing it. If not - now is the time to notice the problem and do something about it.

I am actually looking forward to the day where I get the opportunity to work on the Middle East. Mamluks, Ottomans, Persia... - they all deserve a lot of attention and flavor. However, this day has not come yet.

I hope that is 400 development in the entire country, not in Zimbabwe alone. The megacities have been a plague for long enough.

Embrace Singular Cult seems absurdly strong. You get stronger cult and can change it more often (25 years is very little) and do not lose stability on monarch death. I don't see how anyone ever would use Flexible Cults over Singular Cult.

In fact Flexible Cults is horrible, you should consider removing it to avoid a noob trap or rebalance it completely.

400 development of your entire country.
The Flexible Cults will be not removed. I will consider a change to the cooldown of how often you can swap it though.

Love it! Very much appreciate the new privileges (specifically the one that makes inviting scholars cost no admin, seeing as I rarely use this mechanic because of its repeated cost, despite very much liking the idea of doing so). Also, nice to see these new formables.

Am wondering about the Kilwa-Farsi event, because it seems like you could do this very early but won’t want to because Shiraz will change ownership (likely to the Timurids) in most games, forever denying you the bonuses and events. However, Timurids are not Persian so you won’t then reliably be able to do it afterward.
Is it intended to be a shortlived bonus for an early game boost, or will the best way to ensure it be a long-term strategy of allying/guaranteeing the Persian owner of Shiraz? Or even better: maintain a Persian vassal there yourself (can the mission even be completed that way?)

There are several ways of how you deal with the mission. A vassal is just as valid as an alliance.

Gosh @Ogele ! Until the end I thought you forgotten about Butua! That would have been a huge slap in the face for the sole winner of the region. Will they get Mutapa missions too? Because they should, at least...

Is there new events about Portuguese an Oman's presence in the area?

Edit: Will Mthethwa be on the map as a proper TAG?

Yes, Rozwi has access to Mutapa's missions too.
I have to disappoint you though with the other two questions. I would have liked to add more flavor to the Oman and the Portuguese presence in Africa as well as adding a few more tags in all of Africa, but in the we only had limited amount of time and had to make priorities.

I like some of those new privileges! Would the vassal integration one automatically drop if you no longer have vassals?

Right now, no. But it is worth to consider.

Cool stuff! But this had me wondering a bit:

"Should Mutapa ever lose control over Zimbabwe..." and the resulting modifiers, will that trigger if Mutapa simply loses *control* of the province, to e.g. rebels or a temporary war time occupation, or will it only fire if they lose ownership of it? The latter feels more reasonable, considering how the AI can be with rebels and such!

I am sorry for being unclear. This effect happens when they lose the ownership of the province. The effect will not trigger if the province gets occupied.

I think singular cult is significantly stronger than the other two cults and there is no real reason not to take it over the two other ones. If you want to balance it either nerf it so you can't swap cults or decrease the influence of shrine for heirs and the cooldown of flexible cults. I also think 30% influence for the other privileges is pretty steep, especially when the the most useful policy to my eyes, noble integration policy, is half the influence cost while being significantly better, but I could be missing something.

Religious culture might be a bit overpowered, especially when you consider how it can be combined. Namely you can have - 30% from Spanish holy order, - 25% from privilege, - 25% from full religious ideas and - 25% from enlightenment institution. Between these relatively easy to get modifiers you can lower cultural conversion cost to the minimum trivially easily.

Thank you for the feedback!

Something else I wanted to ask, will Ethiopia be a reformable tag? Or will the Amaharan minors have to form Aksum?

Ethiopia is a reformable endgame tag (though they can form Aksum through their mission tree or through a decision if the DLC is disabled).

 

[Ogele]

Some african love , neat.
though having to wait until 1750+ to try zulu is a bit... i don't know , not many people play that long.

The Zulu can be provoked to spawn much earlier. All you have to do is getting to Mtetwa and Natal, dev their manpower to 8 for each and get to admin tech 15, which can be achieved around 1600.

The thing is, you will not switch your tag to Zulu but swap the country you're playing as to Zulu, which means you will start as a two province minor, so it will be a challenge to play with them.

I know it is not complete, but the ideas are just not okay.

15% morale is supposed to be exceptionnal. Very militaristic nations, shining through morale do not have it. It is extremely high. I am not even sure a single African tag should get it, but here everyone seems to have it... This is not fine, really not.

Maybe ways to get more morale in missions, events or descisions could be fine, but ideas, it is just too easy.

As a EU4 multiplayer player, when I was watching those idea, my feeling be like: WAKANDA FOREVER!

Like the new formables even if i slightly dislike how it feels like every new formable got super good ideas (not a problem for just this patch).

Feels like national ideas slowly get power creeped and the average level of national ideas have gone up patch by patch.

Right before the dev diary I was thinking "Hmm... the ideas seem a little bit underwhelming. I think changing them a bit to make them more appealing would be a good idea. After all, Somalia and Adal got a lot of complaints about having bad ideas in the past DDs". In hindsight, this was no the best idea from me because of power creep - be it through mission trees, national ideas, government reforms or estate privileges - it is the last thing anyone in the team wants here.

I will make a second post later today tomorrow to give an update of the idea changes as well as the changes for the new privileges based on the feedback from the community.

The "Religious Culture" estate privilege should maybe be restricted to Catholic nations only because of how easy it would be to stack it with bonuses from other religions resulting in a clear "best" option. By that I mean, Orthodox gives +33% local manpower, muslim legalism gives 20% national manpower, etc.

Making the privilege available to all religions would result in a clear optimal choice by buffing religions that are already the "meta."

That might be worth considering. I would like to hear a few more suggestions from the community first though.

@Ogele Has reform progress gain for Republics been fixed for Origins?

Great DD btw.

It is one of the very first bugs which got fixed for 1.32, yes.

That's what I like to hear! Something that already has me strategising on the multiple ways you could make best use of it and maintain it.

I can't wait to play the countless nations of Africa that will now be interesting options; nations I've been putting off playing, not out of lack of interest or love for them, but simply waiting for an update like this. What with my personal interest in Africa and the extensive suggestions I've done, some of which I'm glad to see have at least inspired here and there, I'm obviously very happy with the area of focus of this pack, but simultaneously can't help being slightly disappointed with many areas where I feel more could be done, considering its an area that has seem little work and is unlikely to be visited again. With the pack now announced along with its feature list, is there any stuff you can tell us you would really like to have worked on for Africa, but simply did not have the means or time to?

I could give you a whole list of things I wanted to work on for Africa to be honest. Benin, the tags around the Lake Chad, the tribes in the Kongo basin, Southern African tags, a dedicated, scripted migration system or at least a lot of migration events, the Oromo, Madagascar, the Victoria Lake...

I am happy with the content we have, don't get me wrong. It's just that the ambitions are always higher than the resource allowance - especially when you try to think outside of the box, creating mission trees which are a lot more in depth than just "conquer area X, then area Y, here you have your strong perma modifier Z".

axum had control over territories that adal currently controls in 1444, many different ethnic groups were part of the empire (axum) and axum embraced christianity centuries after its formation (in the 4th century ), as such i belive they should'mt be locked to a single religion

it can be like forming the roman empire that doesnt have culture locks

Right now it has the culture lock for Tigray (or be Ethiopia). However, it might be worth to lift this lock after reading this post...

Half the reason I pick a tag to play is their national ideas. Africa and souteast asia usually get a pass from me every game simply because the ideas are so bad/boring. Making the tags more appealing through idea improvements seems like a plus to me.

On the one hand I am happy that the new formables give some extra motivation for players to play in Africa for once, on the other hand I am not too keen that power creeped national ideas have to be the sole reason to play in this continent...

It would be kind of awesome if Zulu were given Prussian monarchy.

... this sounds like fun in theory. I don't know if QA will agree on this one though.

Are there gonna be new tags in the very south of the African continent

Sadly no. We tried to be careful with the tags added because of performance issues. And on top of that, that specific region was the one more heavily colonized by European powers before XIX, so we had to be extra careful about it. However, we're happy with the Zulu getting into the game for the first time.

Kilwa
Impact on the game: LIMITED
Mission tree, NI, play it or forget it, but you already know it

Balance: BALANCED
Even considering the free rewards for the price of one temporary military access for the player (let's face it, I'd love to get Dev data when 1.33 rolls out about how many time this mission is completed by the AI during that time), nothing seems overly strong in this country. One little part to check out is how earlier can Kilwa colonize SEA with this bonus range and potentially get a hold on Malacca trade wise that way

Creativity: SOMEWHAT NOTEWORTHY
The embassy is interesting in concept. Not in execution, but having something as a stronger link that does not necessarily mean a full on alliance and not tying up a diplomat... The gold inflation reduction was predicted previously

Mupata
Impact on the game: LIMITED
Ditto, with the one caveat that one province could end up beyond useless to would be conqueror, unless changing owner also removes the ruin modifier

Balance: SMELLING ABUSE POTENTIAL
Build building -> Exploit dev -> Remove building possibly without repercussion. Money into manpower at a very bad rate since it only works at 1 dev... or getting Dev into negative / rolling back to absurd value due to underflow? Just making sure there. Then again, stacking Build cost reduction might make it worthwhile since the reward will cost less. Ideas are decent without OP bonus either. Zulus on the other hands... starting late, but with one strong military and good conquest based modifiers with CCR and Separatism, I wonder how long it will be before someone find a way to create them, while wrecking the original country for easy conquest right after and go Proto Prussia on Africa

Creativity: VERY INTERESTING
Loving the dev related to building. Now if only it was base game so making related buildings would fuel each other... Ahhh well, one man can dream. As a bonus, moddable Power Projection seems to become a thing


Other formables
Impact on the game: LIMITED
Not going to happen a lot outside of player intervention

Balance: BALANCED
Aksum seems to be the stronger one for constant conquest gameplay but none seems overtly strong. At least nothing silly like free Admin efficiency, CCR above 15% or sailor recovery speed

Creativity: LIMITED
Almost all have Tolerance Own = 2... that is the only observation I'll make there. An indirect attempt at making Religious ideas better?


Privileges
Impact on the game: MINOR
Mostly limited to fetishists, but some more general are also present. Religious culture is by far the most notable on that front

Balance: ALL OVER THE PLACE
Comments on how influence costs are not playing nice with the rest of the game are already out there, but I will also say that a country with only one culture group and 100% religious unity is pretty much 10% richer now. And, it gives more loyalty than influence, making it easier to remove than others

Creativity: DECEPTIVELY HIDDEN?
There's several modding abilities that seems to be present there that could be used around, but maybe the implementation isn't done the way I think it is? Only time will tell


As a personal note, I am noticing the trend of you not knowing how a given modifier works in the game. Not that I want to put your experience in the game in doubt, but I wonder if content creation should be done by two people in tandem, one for the historicity and one for gameplay based perspective to ensure the global vision works as intended. There ARE good ideas too, out there (but, still not sold on TAG magic power)

The building mechanic has been scripted in a way that you lose the development if you destroy the building. Additionally, there is a check to see if the province has only 1 development in a category so it will not go down below 1 at any time.
However, I can understand the concern of having a potential exploit thanks to the interaction of constructing buildings, exploiting the development and the reconstructing the building again. I am intrigued to see if how you guys can find a way to exploit this mechanic to make the micro managing of constructing and destroying buildings worth it.
I also want to point out that the AI does not exploit this feature as a player could do. AI provinces with absurd numbers of development won't be a thing in Africa.

Regarding your personal note: to be honest, I can absolutely understand it. After all, in my very first dev diary, I showed a privilege which reduces goods produced for gold provinces - a modifier which does NOT interact with gold whatsoever anyway.
In the Ethiopia dev diary, I showed a modifier which increases the minimum autonomy globally and the local minimum autonomy reduction is supposed to negate this effect. I learned only later that this interaction was not possible in EU4 - and changing the code of the game for this interaction is not worth the effort as it would break so many things in the process.
What I want to say is that sometimes great ideas blind a designer. EU4 has many complex, intervened interactions, and because time is limited there is always a chance that we notice way later that a great idea cannot work because the game mechanics are not suited for it.
That's why I am grateful for the community to point things out which seemed so obvious to them.

I must say I'm hyped by this and that leads me to the next "joke"

You are like that toxic ex that shows up "changed" several times.

Stop teasing me with a good time! You hurt me! I love you! Why did you do that before!?

Ehm... sorry...?

Okay, I understand that priorities had to be made.
But pretty happy and relieved for Rozwi! Who by the way was an Empire, not a Kingdom, but I get it would be a little bit rushed..

While I'm at it, will there be religious prerequisites to form certain TAGs as Nubia, Aksum or Haussa?
The answer wasn't clear last time (or my question came too early in the development process), but are Congo and Mali formable countries now?
Are some of those new or older african nations end game tags now?

There are some prerequisites to form certain tags.
To reform into Ethiopia you need to be Coptic, forming Nubia requires you to be Christian and to have 10 monthly ADM and 10 monthly MIL to represent a strong ruler.
Same goes for Somalia, though they don't have a religion requirement.
The Hausa actually do not require you to be a Muslim, but if you want to form Sokoto you have to be Sunni.

Hasn't this been available for mods already? At least the Idea groups extended mod and I think the Zimbabwe mod has bonuses to vassalization acceptance.

Yes. This modifier has been in the game since 1.30.