I was wondering if it was viable to specify the first arc and timeskip variant of each Fire Emblem Three Houses character. For example: annette_fantine_dominic, the post #3604920, create annette_fantine_dominic_(academy_arc) or something, meanwhile, for post #3625876, create annette_fantine_dominic_(war_arc); the same goes to fire_emblem_warriors:_three_hopes versions.
That would require quite a lot of tag populating considering how much art of both pre-timeskip and post-timeskip designs there are for all the students. and it just generally feels like character tag bloat.
I don't think post-timeskip designs really needs any distinction. Some FE posters tag post-timeskip designs with official alternate costume but that feels wrong because it really is just a default (not an alternate) costume, even if it comes later in the game. official alternate costume/hairstyle is usually used for Heroes alts or Three Hopes/Warriors designs.
Timeskip used to be a thing but it was deprecated (probably for the better).
Pre-timeskip designs are already distinguished because they usually have garreg_mach_monastery_uniform 9 times out of 10. so really if both 1) the uniform tag isn't there and 2) three hopes/heroes copyright tags aren't there, then that automatically implies the post-timeskip design (or a unofficial/fan alternate costume). if someone wants to see just the base game post-timeskip designs they can just search e.g. felix_hugo_fraldarius -garreg_mach_monastery_uniform -fire_emblem_warriors:_three_hopes (notice most pics have Felix's post-timeskip design).