Got this Unidisk drive a few weeks ago. Unfortunately I couldn't insert a floppy disk, so I opened it, did a full maintenance and changed the infamous shitty gear that broke as soon as I touched it.
My first Apple II demo, Latecomer, loads through ProDOS so it works seamlessly on Unidisk!
I also tried low level access. It's far easier than legacy drives because the firmware takes "high-level" calls 💕
The issue is that you can't really do advanced tricks because all the read and write logic happens on the drive's 6502. But you can upload code on it and even overwrite the firmware.
I don't know if that's really something interesting since very few Apple II owners have Unidisks 😅