I have upgraded my 1230scsi.device to V8.5 with software. More exactly with Blizkick, but I can't see why SoftSCSI wouldn't work either with that.
There's at least V8.5 rom at
http://jpv.wmhost.com/A1234.ROM , but if anyone knows if there's more official place or newer version around, please tell.
Before upgrading the rom, I had some problems with certain CD-writers etc.. upgrading helped.