If anything AI science focus is nowhere near sufficient especially late game.
You know what's funny? Whatever are the science preference numbers: post-April patch, or rolled-back pre-April ones or corrected to have increasing bias with later eras, AI finish times looks like same-ish. AI behaves erratically and lacks focus in any case.
Although it seems that increasing science yield preference in the later eras may be the way worth exploring more. In this case AI has time to establish other infrastructure, including faith and gold economy, and culture, and then raising science focus helps AI to reach 600-800 bulb output per turn or so late game, they have lots of units and more AIs attempt a SV. Arguably this may also funnel them towards a SV in detriment to other types of victories, but as it is very difficult for the AI to stumble upon those victories earlier than SV anyway, maybe this sort of damage is not so big.
I ran another game with increasing yields like one of the tests before, with these settings
and AI does the best for the yields, in comparison to other tests. Trajan blobbed and won SV on T324.
Classical is reduced to 15, Medieval left unchanged at 15, and I added three lines for Renaissance 25, Industrial 50 and Modern 100.
It would be interesting to experiment more with different values and see how they change things. If anybody would like to give it a go, it is very easy, just get
Better Spectator Mod from the Steam Workshop, perhaps
Enhanced Camera as well, for better overview, and you're good to go. The game plays itself, no need to press Next turn, it just stops during Congress votes, then you return to the map and press Shift+Enter to continue. Those pauses are also good opportunities to click and look around the map in peace and quiet. It is very revealing to watch AI only game. And saddening too.
And,
@Aristos, I don't know how to write a releasable mod, my level of 'modding' is to open those files with the Notepad and change some numbers or copy paste some lines. That's it. I know this is not the best way, but I also backed up original files just in case
Anyway, for the endgame, it would be good to teach the AI not to build a carpet of GDRs that are then running around low on uranium all the time, and that's just one among million other things.
By the way, the Deforestation bug that accelerates Climate Change phases screws AI even more than I thought. They start the Flood Barriers, Deforestation jumps from 0% to 50%, then before too long phase 7 is reached and AI is stuck with astronomically expensive FB like this:
And AI will not switch away, AI build to the end and complete them.