i recall when i first got my MSB Select II that we did some testing with HQ Player and by far the best set-up with my SGM 2015 was basically turning it off.....no up-sampling. and going bit-perfect.
that matches my experience, though not with an extreme.
with my totaldac, i found hqplayer to sound best with no upsampling or dither, just bit-perfect.
however, i found that doing this with hqplayer, just bitperfect, sounded better than without hqplayer.
this has been with various versions of Rendu serving as the NAA, as well as running the NAA inside the totaldac streamer.
and let me second the praise for Jussi, who is one of the most knowledgable folks i've met in this field.