Much like imagepoints where you can add more, it would be great to have more collision polygons per Sprite. Current workaround is to create a dummy sprite which is not very handy. You can either have these dummy sprites within a container of an object or you can create a the dummy sprites with actions. Either way this is kind of a pain to work with.
It would be nice if these could be used through expressions using index based collision polygons
Sprite1.CollisionPolygonAt(0) Is overlapping Sprite2.CollisionPolygonAt(3) - or something in terms of that.
Another thing that would be nice is enabling collisions for BBox boundaries as well.
Sprite1.BBox is overlapping Sprite2.BBox