Funny you should ask! I'm currently testing support for C64Cade high scores saving from playing on the Ultimate 64. It's working pretty well so far. After that I think I can get it working from a real C64 using an Ultimate 2+ Cartridge. It's 100% automated, no photos/QR codes necessary!
Wow, that's wonderful news! I'm going to have to buy the Commodore 64 Ultimate, no question. I hadn't thought about it because I have my real C64 with KFF and CRT and I didn't see the point in spending money on this device, but this high score thing is a real incentive to do it, or I'll just buy the cartridge which I'm sure costs the same as the machine😂
Tested it today and it works on real C64 using the Ultimate 2+ cartridge too (also pricey, but worth it!) https://bsky.app/profile/c64cade.com/post/3murqlww4n223