You will probably also want to add `--no-logs-no-support` (don't mind the FUD-y argument name) to the scripted invocation of `tailscaled` here: https://github.com/victoria-riley-barnett/koreader-tailscale...
Otherwise Tailscale (the company) will be collecting your behavioral metadata every time you use your Kindle (what other hosts it connects to, on what ports, connection open and close timestamps, etc): https://tailscale.com/docs/features/logging#opt-out-of-clien...
Yes obviously the actual connection contents are encrypted, but ”just metadata” tells a whole heck of a lot about you: https://kieranhealy.org/blog/archives/2013/06/09/using-metad...