It must be possible to switch between modes. However the Qualcomm Tools didn't make it obvious on how to do so. Judging from the advice from androidunbrick as stated in my post here: https://talk.maemo.org/showpost.php?...2&postcount=26 it's necessarry to have the flashable files to get it to fire up EMMC exposure mode again - and without those files it wouldn't be possible. I don't think however, that the mode that exposes EMMC somehow relies on working partition tables or any files from NAND. It would make much more sense if the exposure itself would remain independent and there actually IS a way to achieve what you're suggesting. I guess without someone with deep technical knowledge in the field, we're a bit stranded :-(