Take the MAME audit and nag screen logs with a pinch of salt. Remember the MAME project is striving for accuracy, and many of these kinds of notes are notes for developers and contributors. This is why I've always removed nag screens from my MAME builds and why I always hand-filter the game selection down myself rather than let programs do it for me, as what's actually playably working is different to what a software report would list as working.