I have only tested the marble suit, winter vest and log suit for this bug. Presumably it happens to all torso items.
Note - This does not occur when Wolfgang is wearing a hat.
Also, Beefalo change size along with Wolfgang. Been in the game for a while and I assume it's not something you guys are worried about but I thought i'd mention it.
Mightify or wimpify on a Beefalo whilst wearing armor.