Pinmame is registered in the registry so it WILL use the same directory anyways. But that’s not a big issue. I don’t see the need of different versions, unless I oversee something special.
regarding 10.7.4 vs 10.8
stick with your old version and be happy. If you use old hardware, especially old 1080p 60Hz monitor for playfield you’ll not care about the new development.
if you want new details, textures, better physics handling and such you’ll better try it.
I understand you standpoint, don’t get me wrong. “Never change a running system”, “why would I want to download huge tables with assets I don’t use anyways?!”.
try it. If you don’t like it change back to your old system. 🤷♂️
drawback will be that you can’t play the new releases. And that’s the conditions that NOT the vpx developers demand, but the table creators.
even JPSalas uses 10.8 for his creations and he’s constantly trying to release stable and small sized versions.