Interesting approach. I read the technology page and the comments about constant directivity reminded me of a paper written in 1971 by Ted Jordan (published in Wireless World) where he argued much the same thing.
Somewhat ironically the Geddes paper (from which the chart showing ideal polar response is taken) ends with this conclusion:
"The take-away information from this last figure is that once one has a well designed loudspeaker, there is no need for electrical EQ and in fact it is likely to make things worse. Acoustic problems can only be solved acoustically, and once that is done, nothing more is possible.”
This is what Ted Jordan aimed to do. I have to admit some bias - I use Jordan Eikona speakers - but my ears confirm that the theory works.