Alec of the YouTube channel Technology Connections has a video[1] about his experience with an E-Ink device on his second channel. He wanted to see if this would improve his productivity, so it's not exactly the same as your question, but it's still worth a watch, imho. [1]: https://www.youtube.com/watch?v=7NfX0vlCa4k
Watching that now. Alec is describing the earlier version of the Onyx BOOX Lumi, I've got the next-generation version (Max Lumi), and there's since been an update to that. Some of the issues (display mode toggling, manual display refresh) are addressed, some remain. The "Navigation Ball" seems to be a new feature of my device not present in Alec's walkthrough, and puts numerous controls closer-to-hand. In particular…
Have you found any drawing apps that work well with the eink screen - apart from the boox one?