does it work backwards like you put the progress that you have made back into the game cartridge/ card
From the FAQ:
Will I be able to use the savegame RAM on SNES cartridges?
A: As far as the game itself supports it, you can load and save games from and to the cartridge. There are at least three scenarios where this is particularly useful: (1) You want to play a game on a bunch of different hosts, just by carrying the cartridge. (2) You want to back up your progress before a battery replacement. (3) You like the convenience of emulator savestates but you prefer to kill the final boss on your good old system.
Yes for SNES no for MD/Genesis.
MD/Genesis srm's can be backup and restored only if unaltered by an emulator.
If you play on an emulator then the srm can no longer be sent back to the cart via the Retrode. It seems if someone made a converter that converts the files from say 16b to 31.9b (original saves size) then it might work, but as of now we don't have such a thing.
MD/Genesis also works in SOME cases, e.g., Sonic 3.
I have plenty of material here. Can be used in daily life, not really.