Now he suddenly had to contend with two remotes, and in order to use the set-top box he would have had to build a mental model of how the on-screen EPG worked, develop some sense of current "location" within the menu, and get to grips with selecting an option - all stuff the rest of us take for granted without a second thought. But because of his failing eyesight, his failing sense of touch in his fingers, and an inability (and yes, a non-trivial amount of unwillingness!) to learn new interface concepts, it was basically the end of his unassisted access to TV.
Anyway, I'm sticking to K-9 5.600 with the original UX because the new one is very wrong for my use case: 3 separate accounts that must stay separate and a quick way to move between them. Given the comments on Google Play [1] and the old discussion on K-9 forums I know that I'm not alone.
I backed up the APK and sideload it on any new device I get, or after a full reset.
[1] https://play.google.com/store/apps/details?id=com.fsck.k9&hl...