That's Good news!
I haven't been streaming much cuz I've been playing Co-op with my roommate on the 360.
I'm surprised at the step back on the XBone, but then again... not really. I also don't know why buying a FiiO would solve your chat problems? And is it too hard to relocate your M-Stage between the TV and your listening area?
Stillie, sorry not you, HOWEVER I publicly posted those thoughts because I suspect many would like to get an idea of ranking hierarchy. So... sorta for you too?
Honestly you have a better setup than me, lol! However, nothing in that setup (AFAIK, I know nothing about Sager and their features) processes virtual surround for headphones.
I assume you are a PC gamer from your DAC selection? If one of your DACs have optical input, you could actually get a cheap device to do the processing (which is the same processing through any product range) and digitally output the processed stereo to your high-end equipment unmolested by cheap analogue conversion. The two models I most recommend for that with optical-out would be an Asus Xonar U3 or a Creative Soundblaster Omni.