@EyeKey Brilliant work mate. What is it that you are doing with the dumps once taken? You said you haven't modified them (yet). This sounds like cloning or can you actually take info from the dump?
I have an issue with trying to use a wfs hdd on a diff wii than the original that formatted it. Very curious about this unique id that is linked and if you can "simply" find and change that id on the wfs hdd and trick the new wii into recognizing the file system. But also thinking that there is surely far more than just something like an id match/handshake that needs to happen when the wii is powered up with connected hdd. At the very least it would be very interesting to see about copying off files from a wfs hdd dump so I could then use those files again.
see thread how-to-use-save-data-from-one-wfs-ext-hdd-on-another-wii-u 515615 for reference (cannot link you since I'm still new here)