Confirmed :-)
during some test yesterday, i've removed the IdeFix software and the passive 4Way adapter, still works with OS3.9 scsi.device. (even the 2nd channel)
EDIT- to be more precise . . . i have an only CDROM on the second channel me too.
I'm not 100% sure, if a HD would work on the second channel without IdeFix.
btw . . . those 4way adapter, ita a DCE CD ROM ADAPTER.