No, I still have questions. They aren't getting in the way of enjoying the sound though!

I am currently operating under the impression that the EQ is applied to each source channel and then the crossover is applied. That means that a +3db bump at 30hz on the front left channel will be passed to the sub if using a crossover (small speaker setting), but a +3db bump at 30hz on the sub EQ will only be applied to the LFE channel source.

I had the 976 on a test bench and was convinced that bass management was being applied to an analog input. I fed a DAC into an analog stereo input then plugged powered monitors into the sub and left front XLR outs and confirmed full range (maybe bass limited?) on one speaker and bass only on the other. I didn't invest the time to confirm that the crossover point moved (previous outlaw products had a fixed 80hz crossover for analog), or that the "full range" was actually bass limited as it should be.

I think "Sub Trim" on the "LFE Trim" menu is for managing the sub gain in modes where channels are summed below the crossover, as occurs with All Channel Stereo and with the "Bass Augmentation" modes.