It'd be nice to have the ability to make a stunt arena, battle tag etc out of a normal map (or vice versa) without having to completely duplicate the folder and rename everything inside for the multiple versions of the same track to coexist. Some parts of the current system seem to already play into this somewhat, such as the distinction between practice stars* and race stars.
Currently my best idea for implementation would be for it to work on a similar suffix system as car skins currently do, where multiple .inf files could be present in the folder (eg. track.inf, tracktag.inf, trackstunt.inf, tracktag2.inf etc). If gamemode-specific customization is needed, maybe a sub-folder (sibling to custom and reversed) with the same name as the .inf's suffix.
*Come to think of it, it would be interesting if practice mode handled the presence of multiple stars more gracefully than flipping a single boolean as soon as one of them is collected. Even if the same boolean was repurposed to "[All] Stars Found" instead of what it is currently. Would probably supplant the use case of stunt arena maps put forward here, but it's not like those are commonplace anyways
Post suggestions regarding RVGL.