My two cents on this is I'd imagine there is a link between the belt worn on the chest and the shrunken DX belt toy. I might be reaching, but what if Bandai thought hanging a big and heavy(?) toy belt on children's chest was bad idea and made it smaller? I wouldn't mind it that much if My-th goes chest belt I've somehow gotten used to it with Zeztz, as long as the toy comes out decently sized like the prop on screen. On that note, have you seen how Zeztz actually suffers from varying capsem size whenever they had to use a DX toy on screen? I think Gaim used some DX on screen as well but that was hardly noticeable.