On a slightly seperate note, and this may be of interest to you especially if maintaining native sampling rates and bit depth is important to you.
My understanding is the CXNv2 up samples everything internally to 32bit 384Khz….No matter what the player is feed.
There’s many links on the net about this, a few on roon forum too.
So no matter what the unit is feed, it resamples internally. But this doesn’t address the upnp issue you describe.