I recall that i read somewhere that the sprite-engine was made similair to the delphix sprite engine, so you could easily port your project over to Phoenix. Delphix has no polygon collision checking so the sprite-engine hasn't it either

Think you have to expand the sprite-engine or just write it from scratch. :?

BTW: I remenber the TestCollision method that delphix had (think it was in the TSprite class).
This was used to intergrate extra collision checking methods (other then bounding rect). It first checks the bouding rect, if the test passes "Testcollsion" is called, wich normally returns true until you override it in a TSprite descendant.

You could add the extra polygon collsion there, maybe

Hope to have helped you