I'd definitively buy one or hell, happy to help beta. My Dillon Autodrive has been churning out .223 and .300 BL like there's no tomorrow.
You would think that a Max10/16 could be converted to 300 blackout pretty easily.
Tuning for subsonics or supers may would be a little difficult. An adjustable gas key would be almost required I would think. I've gotten my suppressed/blackout upper tuned for subs. And while loading my subs with pistol powders, make it a very quiet platform for sure. Much better than factory offerings.
mak91, if this is a direction that you're interesting in going, I would be glad to help you any way that I could. I have a lot of practical experience in this area, and a lot of industry contacts that I could call on if I needed to.
I understand you're wanting to concentrate on the M11, and I understand that. But it's a sincere offer if you do want a hand with anything in the M10 series if I can help.