As far as I understand though, they have stopped offering support for non-subscribers, and they also seem to have stopped producing builds for ARM devices a couple of years ago (but the server software works even with new firmware versions). I am still betting on them supporting local installs for a while (based on my understanding that at least some of their corporate clients would want an on-prem solution), but am a little bit worried it might not be as openly available forever. I am therefore slowly researching my best migration path from a Raspberry Pi to some affordable and reasonably low powered x86 thing. Suggestions welcome.
P.S.: The biggest selling point for me compared with some other (more open) E-ink screens is the battery. I keep mine on the fridge with a magnet and can't really use one that needs to be plugged in all the time in the same place. If anyone knows of anything similar and controllable locally, I'd be very interested to read about it.