I know I made a similar topic recently about a poison max wolver cap, but the alchemy machine is playing tricks on me again and gave me a Stun Max magic hood. This one is a little awkward to sell since I hear at one point Magic line had negative stun stats.
(I have no idea how much this item is worth either by the way)
Concerning my gear, I have no magic armor sets, but I do I have a Snarby Coat, Merc. Demo Suit, and Almirian Crusader armors.
Off the top of my head, I would assume making the Grey Feather Cowl would suit the Stun UV best because most stun sources come from normal attacks.
But are the any benefits from having it on a Divine Veil or Chaos Cowl?
I can't really see any practical use for Stun resistance in PvE, and Magic lines aren't good for PvP.
Indeed, most stun sources comes from melee attacks, which always have a normal component, so I don't think Divine Veil would fit well. Grey Feather Cowl has a huge stun debuff in the first place, I'm not sure it's a good idea to try to compensate it : if you are worried about Stun, you'd want to have an armor that at least don't have a debuff in the first place. As for Chaos Cowl, it's the least bad option, but I don't really see how it is going to help you, compared to another UV.
All in all : yeah, I just don't see the point. If you can sell it, it would probably be a better idea (no idea on the price, sorry).