And just to rule it out officially, guessing the problem is not with the optimizing per se; failed optimizing is just a symptom of deeper issues, and e.g. optimizing with a 4080 but running on a 5080 is not a viable route?
Correct, it’s a deeper issue. It failed to optimized because it couldn’t run the kernels on it.
Also optimizing an engine on a GPU for another one won’t work even with 2 supported cards.