Edit: Hivemind Necrophage has tons of issues. I am extremely dissapointed and Hivemind Necrophages needs changes. I explained it in detail in the link below.
I was real exited for necro hives but unfortunatly they are are far worst then regular hives cus the secundary species can only be livestock, so for the first 10 year you basicly have no main species pop growth, after that, its minimal at best...
forum.paradoxplaza.com
I was about to make a thread inviting you guys to share your Hivemind Necrophage experiences, so I am looking forward to those in this thread.
So far I have tried only Hivemind Necrophage. What I can say is: The Pop Trait is exactly the same is it is for normal empires, only Necrophage Hiveminds get 5% bonus Complex Drone output and -10% Menial Drone Output. +80 Year Livespan and -50% Upkeep. You also get bonus Ruler output which is useless for Hivemind since Gestalt don't have rulers. Please update this with something useful like removing the Menial Drone output Malus for Hiveminds.
Now here comes the interesting part. Hivemind Necrophages get -75% growth like other Necrophages, this applies to pop assembly. And you can only assemble Hivemind pops. You can not use Budding (the 3 cost trait) together with Necrophage Hivemind.
In practice, your Hivemind Necrophage pops are being assembled at a speed of 2 * 0,25, so only 0,5 speed. However, I noticed that the Spawning Drone job adds 10% pop growth speed, but only if you play Hivemind Necrophage. This 10% pop growth speed applies to your non-Necrophage species, which grows at the usual rate.
The non-Necrophage species can only ever be livestock. They are not happy about it which means you get a huge malus to stability. That feels bad given the fact that Paradox just removed Stability from the Chamber of Elevation. On the other hand, the Necrophyte job adds 5 amenities each. Atleast thats better than a Maintenance Drone job. That job is awful.
In my games, I started the game with 50 extra Amenities. You can immediately unemploy 11 Maintenance Drones out of your 33 starting pops, thats 1/3rd of your economy. The rest of your amenities are covered by Necrophyte jobs, Spawning Drones and building bonuses. So you get to play without having Amenitiy issues as Gestalt for once. That feels nice.
Your Necrophage pops get +5% Ruler pop output which is completely wasted because Gestalts have no rulers. Atleast I didn't see any effect of this. Paradox should change this and add a different kind of bonus. Maybe remove the -10% Menial Drone output bonus. It feels kinda bad to get +5% Complex Drone output but -10% Menial Drone output. Keep in mind your Necrophage pops have to do all the jobs for Hivemind. Unless you get another Hivemind species thats not Necrophage, that one would be better suited for Menial Drone jobs.
You can get a Synchronicity Tradition which grants unity whenever a pop is Necrophaged. How much? How good is it? I have no idea. There is no information on this whatsoever. This is missing, please add more info Paradox.
Remember the fact that Necrophages grow only at 25% speed? That makes the cloning Vats from Biological Ascention completely worthless. You are paying 30 food upkeep for 0,75 growth for Necrophages. Not worth it at all. This feels bad. Necrophages should get something useful out of Biological Ascension as Hivemind, because thats all you can do. Maybe add a different kind of building for Necrophages with the Biological Ascension that improves Necrophage pops? That would be useful.
You end up which an insane amount of food with nothing to spend it on unless you take the civic to turn Food into Alloys, which is probably going to be used by every Hivemind Necrophage player.
Overall impression: Apart from starting with more pops, you have extremely ineffective jobs, you have big stability penalties. Your livestock pops only produce 4 food instead of 6 food and do not scale with research or edicts. Its much worse than any non-Necrophage Hivemind since your growth and pop efficiency are terrible. You get 4 pops per guaranteed Habitable Planet so thats a boost. You get reduced upkeep and you benefit from the increased growth that Hiveminds have. On the other hand you sacrifice a huge part of your pop Assembly growth. Overall the bonuses do not make up the maluses.
What I want from the next patch:
Get rid of the Ruler Output bonus for Necrophage Hivemind pops, replace it with something else or get rid of the -10% Menial Drone output malus for Hivemind Necroid.
Add some info on the Synchronicity Tradition for the amount of unity you get from Necrophaging pops.
Replace the Cloning building unlocked from the first Biological Ascension with a building which improves Necrophage pop output. Because paying 30 food per month for 1,25 monthly Necrophage pop assembly is a terrible deal. Or get rid of the -75% Assembly speed Malus and allow Hiveminds to assemble Necrophage pops.