would it be easy to have a “mods” directory at the same level as “data”, and containing (potentially) the same directory structure?
then the first-pass data scan would check the ‘data’ directory … and then would run again over the ‘mods’ directory. this would enable all modifications to be kept quite seperate from the vanilla data - and also for any mods to be flagged internally as they’re loaded.
this would lead on to:
challenges - it’d be easy to see if any modules/hulls in a challenge were mods then, and flag the challenge. (then you could filter on vanilla/extended challenges)
what’d be really really nice then would be if the challenge packed any modified/additional data files into itself so anyone could play the challenge without having to aquire precisely the mod setup of the challenger.