It doesn’t look like one can make his own button combinations for games that don’t have those settings available ‘natively’. I understand that dipswitches need to be particular to each game, but wouldn’t it make sense to make button combinations universal? I still use mameplus0.168 to this day because of its implementation of this. Basically, you have a custom button menu under controls where you can set any combinations you want and assign them at will, and also per-button autofire, whose rate can also be set independently. It’s just perfect.
By the way FBAlpha was already a marvel standalone and as a RA core it’s even better, congratulations. Runs superfast on my i7 laptop in full anti-inputlag mode. I hope it will play Cave SH3 games one day.