I did all sorts of software and format changes. I doubt there was much I didn’t try. Bought a bunch of high res files. Tried from the MacBook, USB storage, network storage. All sorts of interconnects. The more I think back the more stuff I realized I tried.But none of this is very specific and none addresses the ground isolation, jitter or processor load (which generates noise) which are the critical factors to optimize. I suspect that is all your streamers do - all the necessary EE blocking and tackling. But hat can all be done to Roon running on NUC with a RPi bridge - with much effort. Or similarly, some can be addressed with a Laptop especially (since they can run on battery).
That's what I'm trying to understand - and i think is good learning for other starting down the path. Throwing money at it certainly can solve the problem, but takes, well, a pile of money.