By the way, is there an execution hood in this game? Like the ones worn by captives at Abandoned Shack in Skyrim. Just asking...
By No, I mean “not without a way to tell a companion from a player”, that doesn’t make me read their label. There are features of the system that encourage matching outfits, and too many player/companion combos would become identical twins.
Full customization (including skins, polymorphs) - no. They should still be recognizable as who they are. Helmets - are part of clothing, so yes, of course.
I wouldn't want to use use it, but would feel obligated to do so because of the armor value and buff it provides. They would not provide a "hide helm" so I would be stuck. That is just the way things work out around here. I'd rather not if I can't hide the helm.