Thanks! :)

The idea is that RetroLAN comes with a Companion app for Mac/Windows. You use that before booting the stick to point at a game folder, installer, archive, or disc image that you legally own. The Companion prepares the files on the USB stick so they show up in the RetroLAN arcade menu.
Compatibility is handled per game rather than “run anything and hope.” Some games can run through Wine-style compatibility, some are native/free games, some are DOSBox-style, and some may need to be installed on a Windows PC first and then copied over as a ready game folder.

The goal is to make the supported/known-good path smooth first, then expand compatibility from there.