OK - here's what I can now report back.
But first, the short onramp to my recent arrival to this thread starts with me thinking (closer to, actually, believing...) that my integrated was mismatched with my speakers (a fairly recent aquisition). The speakers presenta load of 86db and dippto 1.8 ohms. So, that was enough to search for easier driving speakers because I like the integrated.
Why hear a mismatch? I "knew" my system is better than it sounds (hah!). Tho the tonality was fine up to moderate volume and there was a reasonable stable image, it was presented with feeble bass, limited detail, somewhat thin, lacking gravitas, and weak dynamics. Sounded quite nice, and vieled. Non audiphiles loved it.
After discussions with folks way more experienced than me in these matters, the solution might reside in better power supply - because the solar and powerwall batteries might not be delivering sufficient dynamic current to meet the instantaneous loads demanded by the integrated.
That's how I found Terry at Equi-Tech - super friendly, engaged, interested, articulate, responsive, and, shall I dare say, empathetic, with my goals. Anyhoo - since I have a couple of dedicted lines into the multipurpose room within which my system resides, changing a 14/2 15a 120v line to 10/2 20a 240v to power an Equi-Tech 3RQ might do the trick. Thus my earlier question to the group about in wall wire.
Bingo - the Equi-Tech completely solved this problem. Lots of bass, lots of detail, lots space and depth, rich tonalities, dynamic, quiet. wow. I also sent Terry some of my existing fancy outlets to install, which eliminated that upgrade cost. It's been on for only 4 days, and keeps getting better.
And the in-wall wire, after engaging with Rex offline, and given the several constraints that my house presents, the recommendation was to simply install 10/2 simpull southwire to replace the 14/2 that was there. It's in and it sounds great.