Isn't part of the difficulty with accessing N64 saves in getting the file out in a form where an emulator can use it? The Gameshark method (see, e.g.,
https://www.kyleniewiada.org/blog/transferring-n64-saves/) involves visually inspecting the save file and using a hex editor to graft the save portion of the file into another file for use by the emulator. However, wouldn't it be easier for the Retrode2 if one were only concerned, for example, with simply copying from the cartridge and writing back to the cartridge the save file in the exact format as it is used by the N64 console for backup, without concern for whether an emulator could use it? That is the case for me, where I only play the games on my original console, and want to be able to use the Retrode2 to back up the save files for games where the cartridge uses battery-powered SRAM. Then when the eventual day comes that the cartridge battery dies, I would replace the battery and use the Retrode2 to copy the save file back into the cartridge. For me, some of this is for sentimental reasons - I have backed up the SNES DKK save file where my son (now grown) and his friends pulled an all-nighter to open up all of the levels, and the file where my nephew accumulated a huge fortune in SNES Vegas Stakes as the character 'Mr. Love', and would like to be able to do the same for the N64 Zelda Ocarina of Time save file that my son and I completed together. Not a programmer myself (patent lawyer), so please forgive any ignorance on my part.