This should probably be an AAR but I don't have enough content for that, so apologies for the long post.
1.29.5 Oirat->Yuan 1589 True 1 tag, VH, no loans, no savescumming.
The corruption is not from debasing, but natural growth from overextension and +0.80 from territories for practically the entire game. It helped a great deal with unrest, the most limiting factor of the campaign.
I don't have a lot of screenshots from early in the campaign because I wasn't really planning to go all the way with it until I realized pre-1600 was within reach (and in fact, I beat it by a decade).

GP list with dev

Capital shown on the coast of California, more on that later

Ideas

Tech including 89% penalty on purpose. I dev pushed Colonialism but decided not to embrace it so I could save more points up, corruption also helps with that

Previous rulers including some pretty bad ones, the only proof I can offer for not save scumming. I got pretty lucky with not getting too many stab hit events from overextension. Maybe 10 in total. My last ruler had 0 in admin which forced me into switching religions, more on that later

Economy, the inflation would be from a bad overextension event as I had trading in gems for most of the game and didn't take loans

Forces and army makeup, not a hegemon yet

Saw this decision that gives -1 unrest after sending the final peace deals. I couldn't satisfy the "be at peace" portion since flipping religion.

The final peace deal set, stupidly obscured by my mouse, great job!

Initially intended to show that the AI won't delete boats and goes into vast amount of debt but also shows the VH bonuses

1583

Epic Pirates of the Caribbean sea battle. I lost, but it was very close. Spain had tons of debt in part due to their massive amount of heavy ships of which I killed many in that battle
This run was not intended to be a true 1 tag. I only wanted CNs but no vassals. There were 3 native tribes in the middle of North America (around modern day Wyoming) that were not cooperating. They kept migrating back and forth and were far away from the other tribes that were now stuck in place in a snake (this happens because they reform and then cannot migrate). I needed to either no CB one of those tribes, then take the land from the other 2 bordering one of them, which would leave me with 2 provinces I couldn't core + a vassal, or move my capital to the New World. If I moved my capital I could vassalize the middle guy via a no CB and then core the other 2 of them from having a border with my vassal and a capital on the same continent. Then I would also be allowed to annex that vassal.
So how to move my capital after I have ~11-12k dev in the old world? A couple of guys in Florry's Discord called Bast and Esc helped me figure out a way. I had to split my European holdings from my Asian holdings via vassals or just simply returning provinces to dead tags (which is what I did). Releasing nations would also work but that would be messier. I also needed to filp to Totemist from Tengri and switch my primary culture to a native one (Haida in my case). Flipping to Totemist had the side convenience of revealing all of North America to me. So I also went ahead and flipped Animist afterwards to reveal all of South America. I then flipped Fetishist for the 2 tolerance of heathens afterwards and revealed all of Western Africa. Tengri also has 2 tolerance of heathens and lets me use 100% cav armies (which I was doing for most of the game), but my ruler had 0 admin and needs a score of 3 to enact the decision to give yourself the 2 tolerance of heathens.

This is what the split looked like. Note the 2 large names because my empire is truly split. There are a bunch of tags on the border of Europe. Syria, Aq, Ottomans, Shirvan, Armenia and Qara. Above them is Nogai, Bashkir (who I fed my old capital Bashgird to in a war that I "lost") and Sibir.

Capital has now been moved to California and I am Totemist

Month tick and all of North America is revealed to me

Animist for South America and Mexico

Fetishist for Western Africa and 2 tolerance of heathens. My RU was not great, around 89% even with the 2 tolerance of heathens
A few screenshots that I do have from the course of the campaign:

The state of Europe where most of the remaining OE and truce breaking needed to take place in 1576

I "discovered" Spain very late so I didn't have to deal with them potentially coalitioning me. After around 1540 everyone in the world that could see me had 1000 AE so I was careful about who could see me. They were the #2 GP for most of the game by a fair bit. Many troops and the shock damage received age ability made them a pain to deal with. Having 100% cav helps a lot. I had 500k units but they were conducting many wars and sieges all over the world, plus suppressing revolts, so getting the most out of my force limit without going into debt was a must. This is why pure Tengri is my favorite religion for a horde. Especially if you have no military ideas.

1572. I remember having a serious problem with sailors because almost all of my coastline was trade company (-100% sailors). After I got some German and Italian land (seen here) I built something like 40 heavy ships and 40 transports. To land on GB I stationed 20 heavies in the sea zone by the Isles, and 20 heavies in the sea zone for Orkney. My transports stood in between. GB had ~90 heavy ships but they can't kill 20 of mine before my 37k stack can land with forced march. GB put up a crazy fight that surprised me. I think it was due to the fact the AI was aware that I couldn't reinforce my guys so he was very aggressive in annoying my stack. I sent a mixed siege/battle stack to GB (10 inf 17 cav 10 cannons). I ended up having to send another 25k to help out by getting into a battle with his ships and forcing a retreat into Scotland so my units could land. You can see my 37k stack and retreating ships in the 1576 screenshot in GB.

1559 right after I defeated Austria. I posted this in the strange screenshot thread because it was funny that they didn't exist to me since I could no longer see them. What this screenshot also shows is the method for dealing with the HRE. Almost all of it can't be seen by me so its members do not gain AE on me or join coalitions. I separate peace and full annex everyone in every war that I can. Since the emperor is always a cobelligerent even when you have a truce with them it is easy to eat the emperor very fast. That was useful since Austria got the Burgundian Inheritance and was quite large. The emperor after this was a quite large Brandenburg- to my delight. I ate them and all their allies in chain wars on OPM HRE members along with all their allies.
I wasn't worried about AE around this time and was truce breaking the Ottomans whenever I had a ton of free admin points to stab up. The most efficient way in my mind to do this type of conquest is walk in one direction and annex everything. So my Sunni AE had been crazy high from India and SEA. Ottomans would have been one of the only Sunni's left that could see me since Africa was still not visible.

1557. Truce break on the Ottomans plus war to clean up Eastern Europe. You can see the Timurids are still around, they were 1 war at this point I believe.

1538. Some wars in India to give an idea of the micro. It's a turn based game with this many wars where I have to pause every single day and reevaluate every unit for what they should be doing while keeping track of truces, coring and unrest.

1531. Orissa is on the way to Siberia. That was the initial intention of this screenshot to show that I was outnumbered and they weren't even planning to fight. But it also shows my total troop numbers and composition. I used siege stacks and battle stacks. Siege stacks were mostly infantry and cannons. Battle stacks used no infantry with maybe a few cannons.

1525. First Ottomans war, you can see Muscovy there as well. I prioritized getting the mission for 15% warscore cost reduction.

They had a lot of units so I had to keep all my forces together.

1495. Originally intended to show that I could see Ayutthaya's provinces but had not discovered him. I screwed up and left Ming a border with the guys in SEA. Lan Xang took the Mandate from Ming. The Mandate had to be gone before I could form Yuan if I wanted to remain a horde. Then Ayutthaya took the Mandate from Lan Xang. I became Yuan shortly after this and "lost" my capital to Wu. I moved it from Beijing to the middle of China, returned province to Wu, declared on them and forced them to take my capital. I had developed Bashgird to around 20 and made it correct religion and primary culture to force the move. This allowed me to TC everything (which would later cause my sailor pains).
Overall I made plenty of mistakes that I didn't savescum but it was fun. Thanks for reading.