"... my experience is upgrading a streamer is at least as impactful as upgrading a DAC."
So ... what you’re saying is that, given the same (uncompressed) source file, different streamers send different bits and bytes to the DAC? I can’t believe that to be the case.
One might be able to hear the dfference between compression rates, but even that is hard ... find out if you have a 100% score below.