there's a better solution than all of this. and that's custom firmware, emuNAND, injecting your GBAs into AGB_FIRM mode GBA game .cia's , installing them to sysNAND and emuNAND, and patching AGB_FIRM signature checks on both sysNAND and emuNAND. let's be real here. using flashcarts for GBA emulation on 3ds is outdated and obsolete especially when 3DS can run GBA games natively in AGB_FIRM mode. no retroarch gPSP with dynarec. no mGBA. no flashcarts. the only reason to rely on sky3ds+ to play SNES and GBA is if you were dumb enough to update to 10.4 and lose memchunkhax2 functionality needed to downgrade or install legit .cia's. if you're on 10.4 sysNAND, my condolences. if you're on 10.3 or below my advice would be downgrade to 9.2 and install emuNAND and throw away or sell your flashcarts.