Unfortunately I gave up for now but I planned two things to test for my future attempts;
a) make a custom CF reader from scratch with buffer chips on the data lines.
b) remove the SCSI socket on the DIMM board and fit the CF reader "inside" the DIMM board to eliminate the SCSI cable requirement and to make things more "compact".
The voltage level differences on the data bus and possible SCSI bus (SCSI cable) termination requirements makes my "DIMM" setup totally unreliable which is not what I want in a permanently cabinet setup.
However, the "NetDIMM" + CF setup is 100% reliable with my same cf reader and SCSI cable.
Anyway, I'll probably return to this subject in the future again but until that day, all my Naomi stuff is in a box