so with a hacked bootrom we could make the CFW that allows us to copy/paste the "Nintendo 3DS" folders and make them interchangeable between different NANDs/systems?
nope iirc the movable.sed file is integral to the sd encryption, without having a dump of the movable.sed file then the 3ds cannot read it, and not only that but any installed games would also need to have the tickets installed again anyway, basically there will never be a total freedom for sd files as you always need a file thats locked away in the nand to decrypt them
i guess now though it may be possible to make all systems use the same details to allow a certain level of interchangeability, but honestly its probably a feature not many people would really use as the ticket issue would still exist and really most people don't go swapping sd cards between consoles all the time and it would only be done from the point of installing the cfw, you still couldn't just grab random sd files off a random SD and use a hacked 3ds to decrypt them