BDP-2 brochure says it handles DSD files up to DSD512, so it should do the trick.
DSD is rather new to Bryston gear, so there is not a lot of talk about it when you search back. I am awaiting a BDA-3, which I will be using with a purpose built PC for now. As my current system does not do DSD at all, I can't comment on the process.
You will need some sort of computing device between your NAS and DAC. Streamer, PC, BDA-x, etc. AFAIK, DSD is only going over a USB connection. Perhaps there are some SPDIF, and some I2S based systems out there, but none widely commercially standardized. (There are a few HDMI I2S systems out there, manufacturer specific)
I think there will be more Digital Players over time, the BDA-1 blazed that trail, and many will incorporate the DAC, so the only connection will be Ethernet, and possibly an RCA and/or HDMI to get digital signal direct from the disc.