For what it's worth, take a look at the FlashFloppy firmware for the Gotek:
https://github.com/keirf/FlashFloppy Open-source and handles a lot of different formats. Doubtless the RX50, if not one of them already, could be easily made so. I've installed it on a couple of Goteks and it seems to work okay--do consider replacing the 7-segment LED display with a cheap OLED--more information is displayed. --Chuck
