Thanks for your thoughts guys,
@SixSpeed thanks so much for your thoughts on the REL. They were not on my radar at all so always interesting to learn of new recommendations!

The challenge I have is for the new Trinov bass concert to work you need one channel per sub in the overall array for the concept to work.

The price point and size of this one looks great! I would however run out of channel space which in theory is easy to solve by upgrading to a .24 or .32 Trinnov Altitude one day. The more drivers over a wide space the better. The challenge I would face is the heat + noise of all those plate amps in the room.... When you're running one or two subs it's not a thing. However when you are planning 6 or 8 or more it becomes a real issue within the room as it conflicts with so many other goals acoustically.

This is why I post on here as so many people on here have so many great experiences and advice and NOW is the time for me before I build.

Dedicated theater room: 30'x15'x9
11-4-4 Atmos System. Trinnov Altitude16, 271, DSP750 LCR, DSP7200.2, sides, 7200SE Rear, 5200.2 front sides, 4 x 320.2 atmosphere, 4 x 24" GSG Subs, 2 x Stereo Integrity 12000 (6000w per sub each with own 30amp circuit)
JVC NZ900+DCR Lens Projector, Kaleidescape system.