Mark,
Well done as usual, and fascinating results in regards to the perceived blacks on matte media. I must say, the recent advances in either matte paper, printers and/or profiles are very exciting. I say paper/profiles because even on my 8-year old 7900, I have renewed interest in matte paper. My recent prints with the new-ish Legacy papers have been exciting. Either I am doing something I didn't used to do, or the papers are improving.
All I know is, for me 2017 may be the Year of the Matte. I've had MK selected for > 2 months now; that's got to be a record for me. It sounds like the Canon papers/inks are even better, at least perceptually (pun?). I gave a talk recently and urged everyone who doesn't have at least a 13" printer to run out and get one. As we say, it is a wonderful time to be a photographer. But an even more-wonderful time to be a photographer who prints.
Dave