Once again going out on a limb here, but just not thinking the esteemed member from New England is that passionate about 519a, and is polite enough to avoid saying it for the record, maybe thinking others will be bummed by his opinion? Speculation on parade from this keyboard.
Maestro Malkoff needs to get a small supply of dialed-in 519a variants, including dedomed (any hard users out there?) for him to experiment. Then when his on-hand emitter stock needs replenishment, will hopefully order some 519a to make what he wants to produce.
Another option is for any member who wants to get their posterior in gear and step up with a thread created right here, right now, asking for members to commit to the group buy master/thread starter's choice of configuration. If the required minimum is met, then giddy up!