I'm gonna say no; the default setting is to use the whole drive (I had a '64GB' drive with about 13.5GB of usable storage; even though I had the partition set at 13GB, formatting it with the Wii U reset it to a single 64GB partition and the system choked trying to use it); even if you could, you'd probably have both of them attempting to read the same partition rather than each knowing which was which. Still, I've never tried it so I could be completely wrong.
Don't really want to drag this on since it has been answered, but does anyone have any knowledge of what methods have been tried to accomplish this? I'm just curios as I use to trick the original Wii using my one external enclosure before we could switch partitions. Edit: The enclosure always mounts the second partition because it originally had software on partition 1 that was "undelete-able". Also, I am assuming simple 2 partition setup was already tried as that's what OP tried, so you can count that method out. I understand the contents are most likely encrypted, but I was thinking of using my 16gb pen drive to format with the wii u after blanking it to 00's, making a sector copy and then making a partition after the end of the wii u copied sectors on a new disk.
