I've moved all the posts about
@Bruce00 's playback issues to a new thread for better visibility.
One thing I don't think I've seen mention is that the Quadio discs are authored as 4.0 - there are a number of Blu-Ray players and AVRs (both cheap and expensive, old and new) that don't like passing this format over HDMI, even though it technically is "in spec". I know there was a thread (or two) about this somewhere on here - perhaps someone who was involved in it (or who knows more) can link to them.
One other bit of wisdom I would share - and this isn't in any way to be snide or condescending, it's to save anyone else this same headache - is the old truism of "buy cheap, buy twice." I learned this the hard way about 15 years ago when I got into antique pocket watch collecting - I was bedazzled by these cool old watches, and not knowing anything about anything I started buying up $50 watches to build up a collection. It turns out that watch repairmen are so scarce in modern times (for obvious reasons) that getting one watch cleaned and working is in the neighborhood of $300, and often much more than that if any of the internal workings need replacing. I would've been much better off if I'd learned more about the hobby, bought two or three medium (or high) grade watches, and had them cleaned up. Of course, having my house robbed and the entire collection stolen solved that problem, but that's another story...
I know for a lot of people (and I'm certainly one of them) "just spend more!" isn't a viable option, but the difference betwen a $150 AVR and a $400 AVR (even if you go the used route) is the difference between all these headaches and none of them. Compared to most of the financial titans here I have a really cheap Onkyo AVR from 5 years ago or so, and it handles both 4.0 over HDMI and also DSD over HDMI. I would also be wary of any current model year AVR that doesn't have at the very minimum at least one HDMI 2.0 input because the spec is nearly 10 years old now.
And finally, I'd encourage Rhino to author their future Quadio discs as 5.1 (with silent center and LFE channels) as there's zero detriment to playback for anyone on any system, and it would solve all the problems for people whose older hardware doesn't support 4.0 over HDMI and mean that they could put their disposable income toward buying more music rather than buying more hardware.