You’ll have to do some RetroBat research. It should be fairly easy since it can be done on Batocera.
Essentially, you should be able to (If it’s Mega Bezel presets you are referring to.) disable any shader sets and use my standard RetroArch install instructions. (Double check the shader path in the RA settings.)
Then just load a game in a core, browse to a preset, load it, and save a core, game, or content directory preset.
disable any shader sets
If RetroBat is as much like as much like Batocera as I suspect, then any chosen shader sets will override the RetroArch settings.
BTW. I am fairly certain that RetroBat has my Mega Bezel presets in the content downloader but using it will prevent you from saving any custom changes to your loaded presets.