Regarding Russian UP and building - isn't it a bit too gloomy? Russia certainly is known for more than autocratic tendencies. Among Research Institute (which is honestly even more hot trash than even in vanilla, appears too late to change anything at all), Ostrog from Civ5, Lavra (honestly weird choice, but still) from Civ6, Banya from Realism Invictus, and so on, the Katorga was chosen, and it makes about as much sense as Crucifixion Camp for Rome - totally a thing, hardly something defining. New UP also locks Russia in Despotism (which is not exactly bad and even kinda in line with history, but blocks from even more historic Monarchy/Single Party unless whipping is moving somewhere else) or at least Nationalism (and drafting is hardly required if current UHV stays).
Don't get me wrong, new Russia seems to be very powerful and compensated fairly well (perhaps even too well, whipping is very powerful tool by itself, and Russians got cheap, almost guilt-free whipping) for later start and having to compete with Ancient Rus', but old UP and UBs both were more thematic and arguably better fitting the civilization. It would make Prussian UHV a bit easier, but honestly what makes Prussian UHV a (personal opinion) horrible mess is civ respawns which you can't hard block in any way, at least according to the code i looked at, and not long and boring Russian campaign and dealing with expansion stability blow.
Regarding other changes and new civs: very excited to see them all, and especially delighted by color changes (altho i will miss old Korean color). New Khmer UP initially appeared boring and uninspired, but then i remembered what their current UP is - and it's useful for UHV. France spawn date might be a bit too early and generous, but hardly a game changer. I'm also a bit afraid of SEA being overcrowded, while Africa still remains a black hole, but that's up to Leoreth sense of general importance of regions (and SEA is generally very underrated and underrepresented). Kushans and Vietnamese UPs are probably the most flavourful and useful so far. Poland changing UP again is not surprising (current one is kinda out of place), hopefully this thematic and fitting one will stay.
I wonder how would the game behave with Shia/Sunni split in the mod, but only one civ would follow it at a certain point.
Between fall of Byzantine and possible but not even guaranteed Ethiopia/Greece respawns only Russia is Orthodox (save for rare 3000 BC starts when Catholicism never gets popular). I'd say that Shia would be nice but not really necessary addition, since Shia/Sunni schism is poorly represented by being purely Iran/Arabia+Ottomans conflict (and Iran is almost always hostile to Ottomans and vice versa).
