thank you very much for your effort. So its clear now, that all audiophile user of WindowsServer 2016 will remain outside. The alternative going with WindowsServer 2019 is definitely a step back in SQ - and of course even more with Windows 10.
Recently I compared JRiver and JPlay on WindowsServer 2016 with Audirvana on WindowsServer 2019. For me there is no doubt, that JRiver and especially JPlay have the better sound quality (resolution, soundstage, separation of instruments …) on WindowsServer 2016 - compared to Audirvana on WindowsServer 2019.
However: JRiver and JPlay installation on a WindowsServer 2019 makes it hard to decide. Audirvana has the better (= more natural) sound signature, JPlay and JRiver have better resolution. May be it is a matter of individual taste.
So it would have been very interesting, how Audirvana would sound on WindowsServer 2016. But after your profound research and experiments there will be no chance.
So my conclusion: Staying with JPlay/JRiver.
Again thank you for your helpful work.