The information out there is indeed fragmented, out of date, and not entirely reliable.
There also must be checks in the Classic Mac driver code and probably in the OFW FCODE too. After patching the NDRV section of the rom for OSX to accept my different EEPROM part, OS9 failed to recognize the...
I could have used your write-up a few month ago … I too have recently been down this path. In my case, it was for a Beige G3 DT.
There’s several of threads available online as guides -- in particular: https://68kmla.org/bb/index.php?threads/sil3112-flashing-sata.21640/. But I’ve also explored...
I have a SCSI2SD. With HFS you must stick to a SCSI LUN of 2GB or smaller, so that's what I used. I used HDsetup (or perhaps LIDO) to create a small HFS boot partition for a minimal MacOS 7 install together with the NetBSD install/boot kit, plus a UNIX swap partition and a UNIX root partition...
I installed NetBSD9.1 over a year ago on a Iicx (and I presume 9.2 would be similar). Use an ethernet card and do a network install. I was amazed how easily a current OS installed on a 30-year old machine. BUT: it's very slow to use. I subsequently re-installed NetBSD3.1 which is less resource...