I know this isn't a really big deal in the grand scheme of things, but..
Would it be possible to, sometime soon in the next build(s), make it so that when you move tiles assigned to subscreen elements (2x2 Frame, Heart Gauge Piece, etc.), they are re-assigned accordingly? As it is now, preforming said action leaves the elements assigned to the tiles you selected, not to the newly-moved location
And yes, I realize this is a suggestion, if anything. But if it helps, think of it as a bug-fix; Moving tiles doesn't affect the subscreen elements assigned tile data