Android on e-ink would be a terrible experience -- it's not made for the slow redraws of e-ink. And it's also a lot of bloat to add to these embedded readers with low-powered CPUs.

The remarkable already uses Linux, just not Android. It has a custom Linux OS called "Codex". But you can still get a shell on it (ssh or on-device). See https://remarkablewiki.com/tech/apps or Eeems's more thorough comment: https://news.ycombinator.com/item?id=32119648

You can also jailbreak some Kindles/some firmwares and get a shell: https://goodereader.com/blog/kindle/hackers-release-jailbrea...