I am looking for mods to improve UPS/FPS in megabases. I'm envisioning something similar to Factorissimo2 where production inside of the building is handled in a more computationally efficient manner than the game engine. There would probably be a loss in accuracy to make this happen.

Is this something you're interested in adding? If not, I'm going to try it even though my programming experience is mostly in technical computing (Julia and MATLAB).

I don't plan on abstracting away any part of Factorissimo, since there's way too many uses for factory buildings that can't just be abstracted.

I have imagined a mod that adds lategame abstraction of resource production in a fashion and scale similar to clicker games. I've envisioned the mechanics as allowing you to provide blueprints, resources and construction material to some abstractifying chest that basically adds the blueprints to some abstracted-away factory on some virtual other part of Nauvis, slowed down for balance. The goal would basically be to consume literally all resources of Nauvis in order to launch billions of rockets, and various natural disasters would require manual (or automated) intervention.

Since I'm not planning to write that mod myself, you could have a go at this and tell me how it goes.