What was the most recent version with good performance?

[vaLor-]

I'm not sure what your bottleneck on your system is/was, but a friend I used to play with a few years back played on a potato and so I helped him try out a bunch of mods focusing on performance. The best I've seen/used is Fast Universalis if you'd like to give it a try, assuming it's still updated.

Decided to check the difference for myself in my current run (in mid-late game), used the same playset (map changes, bigger ui, bigger prod ui) but with fast universalis, fps went from consistent 55-58 to 120-130.