I use to set bios roms as “hidden” (you can do this in that page containing each file info: name, producer, cover path, year of release, and so on...)
you will still see hidden files in “normal” use, so I switch to kiosk mode (where hidden files are not shown)
when have to do some modification or trick, I easy switch back to “normal” mode by a short controller combo password (default is up up down down left right left right A B) and then when done switch back again to kiosk mode.
this way everything works great, and I am also sure that casual users (friends, or my kids too) can’t mess up with my system (kiosk mode disables almost all configuration switch and options)