I'm similarly having trouble getting an upgraded SD Card (256GB) properly resized on my Clara HD. Here's what I did:
0. Open up my Clara HD and extract the default SD card
1. Use `dd` to create an image of the SD card
2. Use `dd` to copy the image onto my 256GB Card
3. Unable to use gparted to resize the data partition since it's fat32 and I only have macos and linux devices at home
4. Install SD Card into Kobo
5. Copy KoboRoot-MagicMemory-Resize-3.16.10.zip to .kobo/KoboRoot.tgz
6. Device restart
7. Disk still shows at 8GB, not 256GB :'(
Any idea what I can do next to try and properly resize my data partition? Should I try formatting it to something other than fat32 or might that cause other problems? Thanks for all thelp!