I've noticed with CacheCDFS as installed on AmigaVision that there's a bit of odd behavior with respect to CD unmounting.
If I unmount from OSD, it correctly unmounts...then five seconds later (from the AmigaDOS perspective), is _re_mounted (using cached data?) despite the "drive" being empty. This happens with or without SCSI Direct. Once this occurs, nothing short of restarting the core will make it properly unmount (including rebooting the Amiga!).
Curiously, attempting to eject the disc with EjectCD from IDEFix has no effect.
It's difficult to tell whether this is a CacheCDFS issue or a core issue...any thoughts from anyone who may have seen similar or who has more intimate knowledge of the tech stack?