Among others I have CD0 and CD1 in Devs:Dosdrivers/. In 3.9 I'm using the default CacheCDFS, in my 3.1 boot floppy AmiCDFS and whatever Bloodwych uses as CDROM driver in his 3.1.
You need to have the device driver the mount files points to in Devs as well. The build in controller can't handle CD drives without a proper device driver.
But if I understand it correctly none of this matters if the HDToolbox can't even SEE the drive, right?
No, as HDToolbox doesn't see CD drives, depending on which version of HDToolbox you are using. As the name points out it is for HDs, not CDs.