@uchristo While using dd is an elegant approach (there are Windows versions available, it seems), the tool is a bit too powerful to recommended to the uninitiated, except in carefully specified and controlled circumstances. A bash script is a step in that direction, but there are still parameters the user might need to change for their system, and therein lies the danger.
@paulb_nl The binary import seems to work fine, assuming the SD card has been read starting from sector 1 (offset 512), where the OSSC begins writing to it. The first sector is reserved for any potential future metadata/CRCs.
I am working on an improved export feature, where a minimal FAT16 filesystem is written on the SD card. No promises yet, though.