The Apple SCSI cards tend to be able to find the first partition
nearly any volume from any other SCSI card, regardless of partitioning
scheme or lack there of. The CF card mounting is in reality no
different.
I think this stems from the backwards compatibility of the Rev A & B
ROMs and that they did not use Inside Mac V for their partitioning
standard. But any drive formatted on an earlier SCSI card revision at
least booted on the Rev. C and AHS SCSI.
Seems logical. After all, if you have a 20MB SCSI HDD (for example)
you really don't want to waste any space on a partition table. The HS
SCSI card can just read block zero and check for the magic number to
see if there is a valid Apple Partition Table. If not, just report the
raw disk size through the SmartPort interface (up to 2^24-1 blocks) or
ProDOS block interface (up to 2^16-1 blocks).