It's more the people toggling that you have to watch out for, and they would obviously toggle off as soon as an admin was present. Admin skins could be cool, but the admin tag would show if the admins were in Spectator.

Maybe if it was an added extra in the starting menu? Like you have skins 1 to 4 on each team at the moment, it could be another one of those so that the admin could choose whether or not they wanted it on? So like, if we were playing on the scrim server or whatever.....I dunno, it's a nice idea but I don't think it has many practical applications.