Boox devices are also very accessible as the run Android and you can install anything on them either from the Play store (requires manual setup at first) or F-droid, along with the usual adb access. I have the Nova Pro which I absolutely love. It has configurable screen refresh rates so it's possible to use a web browser with scrolling. You can install your favourite file sync app. Lately I've been using KDE connect to send/receive files. Writing on it is good and the notes app supports OCR that I found can make reasonable sense of my chicken scratches.