yep, it kind of uses the same principles as the LX521, only 3-way, and i used a waveguide to match the forward dispersion of the ribbon to the midrange.
the reason i chose the JA8008 was that it had nice and even dispersion all the way to 2500hz in a minimal baffle, so it could reach high enough to be crossed over steeply with the RAAL.
i probably did sacrifice some controlled directivity past 70 degrees due to the side supports, but i built a prototype with and without, and they measured pretty similarly, and i couldn't really hear a difference, so i kept them.
visually it was a big improvement
i did try out a dampened u-baffle as well, but never could get it to measure like a cardioid, so went with an H-frame instead.