Don't hold your breath. I left a number of messages on their website over several years and even talked to one of their managers about a group buy. Bottom line is the design costs are high and the 3d gens are out of production and they'd never recoup their costs (which they claim are in the neighborhood of 250k).

The LG359 model for the 59xx series can be modified to fit the 6906 and similar doublestacks. Takes a bit of work, but not a lot of genius.