Just wanted to report this one, it's pretty glaring and I don't think anybody's thought to try it yet. I set up a frame with two layers, one with 0.5 scrolling co-efficient, one with 1.0, both of which set to wrap horizontally, and I set the frame's virtual width and height to -1 for infinite scrolling. The result was a visual disaster of epic proportions!
The frame started off with no backdrops, which then scrolled on after he passed the width of the frame, then about half a frame further a copy of the frame started overlapping the previous one, and more and more copies of the frame overlapped each other while the framerate dropped and dropped to unplayable levels.
Glad to be able to report it!