lwin, nice explanation of your priorities in setup. The extreme toe in would explain, I think, some of the discrepancies between our experiences in hearing the Tekton array. Ah, Ulfberhts; mea culpa for calling them Moab. Go big or go home! ;) Bill Dudleston of Legacy Audio sets up speakers such as the Whisper similarly, with the axis of the L/R crossing before the ears, though not as extreme. I get why you are doing so, to share the sweet spot. Hopefully your new seating will resolve the issue.
I think you will have a lot of fun trying the Wharfedale speakers in the big rig. It's always a learning experience to set up a new rig. It is one of the greatest joys of the hobby for me, like cooking with sound, a unique feast served each time!
viber6, I wish I had that kind of sway, that I could urge and manufacturers jump into action on a new build. That has only happened one time, with the Legacy Audio Whisper. I wanted to review the Whisper, but it was an active speaker requiring triple everything (cables, amp channels, etc.), which was prohibitive for me. I said to Doug Brown, Bill's business partner at the time, can't Legacy make a speaker that can switch so I can listen to it with a stereo amp and try-wire, and also use it as built. Doug said, "You challenge Bill to make it!" I said, "I'm not going to challenge a designer to make a product!" He said, "Then, I will!" And they did! The result was the Whisper DSW, originally named after me; Doug Schroeder Whisper. It has 12 sets of binding posts because it is what I call in the review a "crossover speaker", for it allows 3 configurations; fully active with six channels of amplification, hybrid with active bass and passive mid/treble, and fully passive with as little as two channels of amplification and try-wiring! I LOVE it! I have built SO many amazing systems with it! Legacy has incorporated the hybrid element into several of their speakers, where an owner can select the operating mode.
Later, I also requested Bill to work with me on a review in which an assessment of the efficacy of upgraded internal parts was the topic. The speakers were returned to Legacy, where it was rewired with 10AWG Clarity Cable throughout and caps replaced with Clarity Caps (no relation to Clarity Cable). It was called the Clarity Edition. So, the speaker now is the Whisper DSW Clarity Edition. I have reviews of the entire process at Dagogo.com
In regard to your dreaming of a concave ESL speaker, it sure sounds fascinating and I would love to review such a speaker if it was built! But, though I am not a designer, nor proficient in the math, something tells me it might be untenable. I ran stacked Eminent Technology LFT-8 speakers for a while, and though it was terrific fun and huge sounding, It was less coherent than other designs/setups. I'm wondering if the concave stereo effect might be too beamy for its own good.