Two things about optical and coax that I noticed. I have an ifi zen one signature dac. Sounds way better than built-in dac. But when connected via optical it can only accept up to 24/96. Plus sounded like a bunch of hi frequencies were missing. Tried different optical cables with no difference. Thought my LRS+ were just weak in the highs. Hooked up via coax and noticed it can work up to 24/192 with no noise from ifi dac. Plus I could hear much more high frequencies. Not my imagination but fact. Even when I reduced the coax output to 24/48 high frequencies remained. Overall very pleased with the unit.
Zen one is likely not to accept 24/192 in optical. Multiple users have already reported it.