I completely plan on making my MMC5 rpg working on the real thing. That is what I plan to do and I'm completely determined on fully understanding the MMC5 by making a dev cart of it and testing thouroughly all of it's features and stuff and finding exactly how it runs on real hardware (I'll prolly buy a few MMC5 games to study them neway.....I already have Castlevania 3).

Although I do agree that non-working stuff coded for the NES is a problem, but not so much anymore. All the emulators are really accurate (theres a few odds and ends but they are really close) and I don't think that people nowadays could write unworking demos (although there is a chance.....I've done it) that work on those things and not on the real NES.