After looking around some more I finally settled on the Pioneer XDP-100R. Physical volume knob, more recent version of Android (than Sony, who are still running a 4.X version as opposed to the 5.X version running on the Pioneer, and yes I know it isn't the latest), two MicroSD slots, upcoming MQA support, cheaper than the Sony ZX2 (even a used one).
Everything else out there seemed to have *some* kind of compromise, whether it be cost, lack of a feature I wanted, an older software version (once I decided I wanted to run Android), or some such. I ruled out the ZX100 because I want to be able to run Tidal on the device, and that one doesn't do Android (but I suppose that has its advantages as well).
We'll see how it sounds!
Thanks for the tips!