This is something that I would like to see implemented for the Pro firmware, especially for people who use Japanese Mega Drives to play their games on. I have a NTSC US console, so I'm unaffected by the issue of English translations not working as intended, but... changing ROM regions was an available feature for the older X7 OS, where you can choose custom region for games. Does seem quite odd to me personally that this feature wasn't implemented for the Pro firmware, at least as far as I can see.