fix it so it works properly and it's user friendly and I'll make a donation
Should just be an option in groovyMAME to use neogeo modified widths. So don't have to stretch all the individual games, that would be an easy thing to add, and user can have that option on or off. No need for using multiple mames then.
In the old days it would be 1 game per monitor, so stretching just once is easy (analogue quick and simple) and just would be left like that, but when you're using one screen for multiple games, you want the screen to fill up and not have unnecessary borders each side don't you?