linknet,
Indeed I ended up sticking with A&K's "supported" suggestion as to which version to use (V5.19.1.2) for the SR25, as less than an hour later after my previous post I had a few tracks missing from my first imported albums, and wanted to avoid stress during my commute the next day. Indeed V5.20 is better than V6, but V5.19.1.2 ended up being the most stable, as I have been commuting all day long, just got home, used the player almost non stop, and no tracks have been missing. Even with a few hiccups when the system detects wifi from the subway stations (granted about 3 all day long), in which audio pauses for a second-and in which time I thought a track was going to be lost-that version is rock solid. Works well and a bit faster than 5.20. So yes, I can also double down on that recommendation-the SR25 can enjoy Qobuz, but mostly with the recommended version-the latest is a mess in comparison, as far as the SR25 is concerned.
Perhaps for my Samsung Note 9 the Qobuz V6 will work fine (and it does not sound too bad even despite the Qualcomm CPUs, just a bit bright which sometimes is good... also not as much power as the A&K), but most of my music playing will come from the SR25 moving forward, relying on the phone only when it is more convenient.
Thanks a lot for your help. No missing tracks meant I was able to listen to a whole opera without missing tracks, and the non classical albums were also intact. I no longer have to worry about an incomplete musical experience.
(Wish there was a way for the latest versions to be "the best" for every device, not just the most powerful Android systems.)
So SR25 users, use whatever A&K recommends for Qobuz, so you get a much better user experience. I was going to quit the service just because how bad the latest app is!