To get it out of the way, I think we can all agree that tmogs are single most important matter in this game.
But jokes aside there are some inconsistencies with tmogs, or rather oversights for improvent, and to be more specific with weapon tmogs.
My issue / example here is with one hand weapons like swords and fist weapons on the other side.
So for swords you can get a tmog from a main hand specific weapon like Phantom Blade and you are able to apply it's tmog on your off hand sword, which is usually a non specific hand weapon (I don't know if there are off hand specific swords available in the current phase to test it further)
Now for fist weapon tmogs, or rather fist weapons in general they are basically always of the main hand or off hand specific type. Here you are not able to apply the MH tmog on the OH or vice versa. The issue here is that many fist weapons don't have a visual fitting counter part meaning you never get a matching pair for some. Now some would say why does that matter it's just a tmog and just wear not matching visuals then. Well I ask why are fist weapons left out here, over all less customizable and suffer from this restriction the most? I just would assume it is caused by the specific "hand type" and it's not allowing it because of shields and caster off hands being in the same category.
My request would be to lift these restrictions for fist weapons and maybe even all actual weapon types to have an easier time getting your favorite visual match and leave the restrictions in place for shields and caster off hands so they stay as a purely off hand tmogs (even tho dual wielding shields would be hilarious).