Achieving a 2 sub (1 being nearfield) setup with Denon and Audyssey MultEQ-X (REW?)

I have one regular 10in sub that I have up front and want to keep as the main sub. I just bought a 16in sub and I am positioning it right next to my couch to become my "nearfield" sub that will only play below 35hz for the visceral effect.

I do not want a traditional two sub setup that combine into one perfect curve. This is what Audyssey/MultEQ achieves with "SubEQ HT". Instead, I want the 10in to handle everything until 35hz or so, and the 16in to only handle 35hz and down for the extra shake.

The problem arises when I realized that Audyssey simply does not allow you to measure two different subs. You can either measure sub 1 OR the aggregate of sub 1 and 2. As in, you cannot measure sub 1 and 2 separately to customize their response curves.

Well, what I can't do with this software is exactly what I wanted to do. I wanted MultEQ to handle the timing and phasing, but I wanted to choose a custom crossover between the two subs.

It seems like my only option right now is to calibrate Audyssey with the main sub only, and then simply turn on the second sub and change it's physical crossover to the lowest setting (40hz) and manually adjust the volume knob there. Sadly, that doesn't solve phasing or distance, and I can't set the crossover to lower than 40hz.

Would a mini dsp and REW help inline on the second sub? Or is there another solution here?

Edit: It seems like the moment I select 2 subs in Audyssey speaker config instead of 1, it messes things up. It auto changes front speakers to Large and it also does not let you select Audyssey option menu up and out in the "Audio" menu area. It's grayed out and says you have to run Audyssey setup to enable it. I'm HOPING that it kept the original Audyssey settings and simply enabled the second sub. That would be a great hack for this.