MiSTer’s NES core is getting Nintendo Famicom Disk System (FDS) support care of GreyRogue, making it the first FPGA system that natively supports FDS without needing additional hardware to load ROMs. The same update also adds expansion audio for VRC6 and Sunsoft-5B mapper games (Gimmick, Akumajou Dracula, etc). For a first release, it’s relatively mature. With time, FDS game compatibility will improve and the audio will become more accurate but you can try it now thanks to Rysha’s custom preview core build.
Rysha’s NES+FDS Core Build: https://github.com/Kitrinx/MiSTer_NN/tree/master/NES