Awesome job Bart, all that effort has been worth it
If racing game, and mouse enabled, allow mouse to act as the driving wheel, for sole useful purpose to allow for accurate race course selection. A left / right sensitivity setting would also be most useful too (if that is even do-able).
e.g. supermodel roms/scud.zip -mouse_sensitivity 50
NOTE: i did read your not accepting user requests at this time, but i feel this feature alone would make a huge difference to racing game selection screens.