@j.p.s: Yep, see
#75 
.
It *could* technically apply to Zelda/Rex, but I don't have any of those devices, and I've never seen any strace from 'em when displaying image content. But I'm going to assume that, no, the HW feature is never actually used, so screen grabs will do the job just fine.
@ilovejedd: Oh, fun

. Not terribly surprising though, I'm pushing 55fps on a Forma w/ my crappy port of the doom fire effect ;p.