Didn't have much luck with it yet, I'm afraid. Tried both XP with WinUAE and FreeBSD with e-uae.
winuae.exe -disableharddrivesafetycheck sees the harddrive now and I can use it. HDinsttools recognizes the drive correctly, but I am not able to partition or format it. Changes don't seem to be saved, I can't even add Smartfilesystem to it (yes, the drive is set to r/w in WinUAE).
e-uae 0.8.28 shows the drive on the desktop although there is no partition on it yet. HDtoolbox which comes with OS 3.9 doesn't find any drive at all. (What's also strange: I also seem to be unable to mount the hardfile of ClassicWB with it. The drive icon is there, but it seems to be empty). :-? :-(