The announcement for MODE mentioned that games are region free- while I don't know how specifically you guys achieved this on Dreamcast it's generally done (for other devices/CDI rips) by modifying the IP.BIN file for a title to indicates it supports all regions. On Dreamcast another common modification to make to games is to change the IP.BIN to indicate a game supports VGA output (a '0' or '1' value located at 0x3D in the IP.BIN file); this allows you to play the game using the best form of video output a non-modified system supports. Not all games support VGA but many of them do even if they aren't marked as supporting it (and if their IP.BIN doesn't indicate it supports VGA the Dreamcast won't normally boot it if the system is using VGA output). Any chance the MODE could (or already does) auto-patch Dreamcast games so that they will boot when using VGA, even if they don't normally indicate support for it?
Given not all games actually work properly with VGA, it could also be worth making some kind of advanced option to enable this patching.