Personally, if it were reasonable, I'd allow it. The universal Item of Power sub-power, "It Is What It Is" does allow for all sorts of interpretations. A Sword of the Cross, for example, gets to act like a sword in all ways, for cutting, parrying, prying, leaning, and stirring. I can't see anything wrong with the same thing applying to a suit of plate armor. Of course, since it is what it is, you'll also have to contend with the weight, the heat, and the laughs...