If I'm interpreting what this device does that explicitly makes it Mac-friendly correctly, that depends on the Apple IIgs working well with the same SCSI devices Macs use. However, for IIgs there are also lots of other extant options including the focus IDE card (what I've got in mine), floppyemu, which will run smartport HDs on the II, and CFFA, which operates on a somewhat similar concept to this, except that it has an inline control panel for image swapping.
@ymk - welcome in!
With regard to >4GB images, I'm curious what the demand for that is like. Only '040 Macs will officially run volumes over 4GB, and your'e kind of getting closer at that point to the brief window where the SCSI2SD v6 makes more sense, for performance reasons, and then after that, where SATA cards make more sense. I can imagine a couple use cases for it, myself, but I'm also among the relatively few people I'm aware of running 2TB volumes Classic Mac OS at all. (Although, like,
With regard to partitioning, what would that look like in terms of setup and configuration? It would seem like the biggest advantage you've really got here is that this device was "designed with the needs of the vintage Mac community in mind", I feel like it would be fair to describe it as explicitly to the exclusion of other platforms and applications where scsi2sd is also used (i.e. it's unlikely one of these will work in a synthesizer or a traffic light or a UNIX machine) and a big part of that is the simplicity afforded by the way this thing is configured.
The people among us creating SCSI2SD preloads would be able to change to just zipping up the contents of the FAT32 filesystem as a download and people can avoid, say, DD or managing partitioning entirely.
If this is in the docs, you can be like "hey, uh, RTFM" and I will at some point. I don't have the budget for one of these so this is purely speculation on my part.
All eight of the indicator LEDs on the edge can be mirrored to external LEDs. Nine pins on the expansion header can be used for LEDs (eight anodes and a common cathode).
I've done no testing with Apple II.