Thanks for those curves. Perceptual bass boosts for listening lower than reference, totally makes sense. I've been starting to play with that lower Dirac cut-off curtain, and just letting the subs go hog-wild below 30hz or so. In my car I think the lower curtain is at 40 or 50hz even, let there be boom! Theres so much low end road noise that one needs to crank the sub to hear it over all that anyway.
As for the smell, yes! I can confirm I had a smell as well. Initially I had wired in the subs and the mains in parallel on the each amp ch (thats why Dirac in the graph above is showing a full range response on L and R). That would be a load slightly greater than 4ohm, but class D and low volumes, I thought I could hack it. Smelled that after a few tracks and promptly unplugged everything. Wired it back as 4ch with an aux amp. Havent smelled a thing on day 2 or day 3. Its been about a week. Havent even turned the bugger off yet actually.