Pretty much everything said about center to center driver alignment is true and well verified by the research Meyer Sound has done. The real problem with home line arrays is most designs choose to make due with heaps of domes and large-ish mid-range drivers. You simply cannot build line arrays from 1 inch domes or 5 inch mid-range drivers and have it adhere to the principles of line area theory, unless you do something creative like simulate smaller drivers from larger drivers like Nexo did.
Why so few high end line arrays?
To me the intrinsic "wall of sound" of this design are compelling. I recently tried a very nice 3 way w/ stereo subs in my system after 2 years of line array-only listening and the lost impact and scale of eight midbasses/ribbons per side was profound. I was immediately aware of the music emerging from boxes, despite very nice imaging. And it's not that the arrays exaggerate the size of voices and instruments. Does the materials cost dissuade manufacturers? Is it the size? Seems like relatively unexplored territory in high end home audio.