Unit pathing in FAF tends to get hampered mid to late game by the units colliding and bouncing off of each other especially when trapping each other in a base. This can have a fairly large impact on the games sim speed and be quite annoying to deal with. (player has to spend time sorting out units instead of progressing)
Turning off collision outright would be a terrible solution and the flying engineers mod only solves this issue for engineers and it creates a host of game balance issues. A better and fairly simple solution has already been done in Supcom 2; a sort of rubber band collision physics where units don't actually collide but instead push each other more based on how close they are. This allows the units to flow a bit like a liquid and prevents them from getting jammed.
I have no idea if this would be possible to implement via a main FAF update or via a mod. I don't know if anyone else even likes this as an idea or if anyone is capable of implementing it. I'm not a modder myself and I just think that this could be a quality of life and possibly a performance improvement as well to FAF.