So the issue was more that dual-link DVI was very rare, and getting hardware to encode/transmute it reliably and at high bit-depth was almost impossible.

By about 2014 hardware encoders were good enough to send decent quality video over gigabit.

Somehow those didn't show up on my searches, though it was a few years ago.

Thanks though, will keep it in mind. These days Steam Link is decent enough for what I wanted, but ya never know.