Thanks for a great reply. If I was employing a second row of seating with leg room I would definitely need to reconsider the calculator and move the screen higher. Part of the decision to go this screen size and seating distance was to meet audio criteria first. The speakers and mlp within room serve to satisfy best modal behaviour and 2ch setup ratios. Pretty much the entire build was audio centric in the design phase.

I had to decide if all LCR speakers would live behind the screen and go bigger, but space the LR channels narrower, or go smaller and land the LR speakers closer to a 2ch configuration outside of the screen envelope. I chickened out when I considered the tower speakers interaction with the screen frame and support structure. Smaller screen, wider placement won out. In the end it all is panning out, but making those decisions wasn't easy at the time.