It is a great job you've done and I hope you continue to tinker with it. There are coders on this forum that have "retired" that might be pursuaded to come forward to give suggestions if you're continuing.
I used to like playing this game on my A4000 + Picasso IV using the
RTG Master patch but it was very buggy and crashed a lot but it was soooo much faster than AGA so the occaisional crash was not enough to put me off using it.