I do not think any item what do not have tiles at all will be shown, so no worries. This is only for existing items in my tileset, what do not have wielded graphics.
And ofcourse items what already have graphics for wielded state will not be affected. Only the ones what was invisible when you were wielding them.
Yeah, and ofcourse you will not see giant letter on your character, if you wield an item what do not have tile yet.
If it was the case, i would be wielding giant D in my hands on any playthrough. 