Thank you! I also had trouble with poor performace, on a RTX 3080!
I think the problem has to do with the software not recognizing modern gpus. I was able to fix some other 32 bit games from my childhood with some programs, but I've not been able with SCS so far.
For example, I managed to fix an old cycling game crashing making it use 2 gigs of vram, instead of only 128 mb it recognized intitally. I think if we could trick the game to use the power of modern gpus it would work much better.
Edit: oh! And something you can do is patching the exe to use 4 gigs of ram instead of 2, as it is a 32 bit app. I haven''t noticed much performance difference after doing this, anyways. So I think the main culprit here is the GPU "cap".