I see what you mean now. I've also wondered about flipping sprites with regards to the hotspot position, although not with the idea of scaling to those magnitudes.
I suppose you could mitigate this problem a little, but not entirely, by using double or quad sized pixels (i.e. hs at [3,3] on an 8*8 sprite). If the hotspot is in the centre of this chunky pixeled sprite, it won't shift so much when you flip it.