No D3.1 hardware is certified at this point, the chipsets are just barely out and still experimental. Customers probably won’t see D31 hardware before 2016. 

Btw, in my experience, modems and CMTSes have no AQM at all configured. And the buffers are large, in both directions. The more recent the model, the more buffer it usually has (hey, more speed requires more buffer, right?). I’ve seen multiple Mb in some models, can’t remember the exact amount, but it might have been 2-4 Mb for my current TM702. So the worst case is actually to have a very recent modem with a lower-tier speed (like a 10 Mbps). 

JF