Due to my own ignorance, I didn't realize I needed a different adapter other than the one included with the unit and merrily plugged in my brand new SCART cable into my brand new Framemeister. Now I am reading like a hypochondriac addicted to webmd that this could potentially damage the unit, and so naturally I am freaking out. The unit appears to be powered on and working via composite and S-video ports... has anyone else made the same mistake that I have?
If it's still working, you should be fine - the main risk is that if you connect a SCART cable that has a non-current limited supply on pin 8 then you can blow out the ground tracks on the socket (since that's a ground pin on the Japanese 21-pin AV). There is also a potential issue with pin 16 - it's a switching input on both sockets, but SCART is rated to allow 12V on this pin and the Japanese one isn't.
Thanks for your replies. I guess I will find out definitively once I get the SCART -> RGB-21 adapter and see if the RGB port is still functional. If not, hopefully it will be covered by warranty or would at least be repairable
The seller I bought my NTSC SNES and Sega 32X RGB SCART cables from sells this adapter for the XRGB mini. They also have an adapter with a powered sync stripper if you need it. It might be easier to get one of those than to track down a SCART to JP-21 adapter. Another alternative is to make your own SCART to JP-21 adapter or rewire the adapter included with the XRGB mini.