I'm guessing you'd have to change this in the even sheet:
Draggable| On DragDrop drop
-->System | canFit = 1
----> Draggable | Set position to DropZone.SnapX(Self.X + 16) - 16, DropZone.SnapY(Self.Y + 16) - 16
To half the size you want as it is using the origin of the tile +half the width of your tiles
And then for both Tilemaps (DropZone and Draggable), setting the Tilemap width and height properties to the tile size you are using (set to 32x32 right now)