I have not.
I did ask the folks at SEAS about this cone a few years ago. They conveyed that development consumed a considerable time and the cone was VERY slow to arrive. They also conveyed the standard Magnesium cone driver would continue to have vastly more favorable distortion characteristics.
However, there is a new driver from SEAS that does appear very appealing to me. The H1456 is quite cheap and appears to have all the goodies in the motor.
I really wish I had more time for experimentation. I have been working very long hours recently. Also, having a 3rd child has joyfully consumed a plethora of my time.
Completing the Accuton project is on the top of my list of things to accomplish in the workshop.
Dave