Bad link. It’s actually the “tiny” form factor, not the SFF version that I purchased.
OK, I cruised the forums and read other posts for awhile this morning. I was wondering why I wasn’t seeing bitrate information in setup options like others were. I realized I was configuring the system output, but not the Intel Display Adapter. I disabled the system output and opened the Device Playback Settings. Made adjustments there, turned off PCM, enabled DSD64 and set outputs to 2CH. DSD64 seems not to work, but I now have a Lossless path, from High Quality before. Material sounds better, too.
Quick update: My wife and I greatly disliked the sound of the Windows PC over HDMI, so I returned it. Yes, I could have kept it and purchased a DAC to go with it, but that seemed to be somewhat foolish. I’ve decided to put this topic on hold and think harder about what matters. After all, getting Airplay via our new AVR is new to us, and not such a bad thing. I started to feel like I was chasing magic settings and certain colors of data displays, which is not really the point. Thanks for your help. I’m going to do more reading and learning before I open my wallet again. Lesson learned. 
Much appreciate the help, recommendations and assistance from the community. David
Came to this thread late.
I have inexpensive stuff, also. DietPi endpoints with an IQAudiIO DAC, a HiFIBerry DAC and iFi and Schiit DACs. Also an Onkyo receiver.
For my money an external DAC can’t be beat. You don’t need to go high end to hear the difference, a Schiit Modi or one of the cheaper iFis would be a good place to start. Be careful, as many will attest, upgrade-itis can be a real problem.
Airplay to my Onkyo, or to any receiver, is really the lower end of the possibilities.
Have fun.