Alright, so here is an idea I have...
I have an SNES Classic, I really like the little system and I love using Retroarch on it to play the games... but something I've always wanted is to be able to have Gane Genie for each of the systems, the actual Game Genie, not the "cheats" feature in Retroarch. What I think would be cool is to be able to have a program / util that would take the Game Genie rom for that particular system and attach it to the rom of the system. Let's say I want to have Game Genie + Super Mario Bros 1, the util would take the NES Game Genie rom and attach it to the SMB1 rom, so that when I stick that rom on my SNES Classic, the Game Genie screen comes up before the game and I can input my codes.
If I wanted to do that to a Snes rom, you select the SNES Game Genie and the rom and the program combines those into a single rom. I don't think something like this is unfeasible. I mean, if something like Super Mario All-Stars NES can be done, where it's fusing Mario 1, 2, 3 and Japan Mario 2 (Lost Levels) I don't see why a util to fuse a Game Genie rom to a game rom can't be done. It would need to be able to do NES Game Genie, Snes Game Genie, Sega Genesis Game Genie. Maybe GB and GBA too if you wanna go the extra mile.
Why would I want such a program? Why would I want to add Game Genie onto individual roms when Retroarch already has a cheat feature? Authenticity and nostalgia. Why else? Because seeing that screen come up before a game loads brings back pleasant memories.