The answer to this is probably no, but neither the wiki, myself or anyone I've spoken to have been able to deny or confirm this... but I was wondering.
Say you have a UV on a weapon that isn't 5 star, if you were to upgrade it would it be possible to gain a second or maybe even a third UV through crafting?
I know you can get 1, 2 or 3 UVs from crafting, and you can add extra UVs with Punch, but I have no idea if it's possible to gain any more from crafting.
If you can, the chances are probably extreme rare, but is anyone able to confirm or deny this?
I don't think it works like that. When just crafting, you have the choice to lock the UV(s) you have or not, which either keeps the UV you have or resets all possibilities, while using Punch allows you to keep a UV and roll. For instance, you have one UV on something, to get two UVs on it you would have to use Punch to lock the UV on it and pay for double UV costs.