I have searched for a way to use my Xiaomi Mi A1 phone. I want to use it as a personal cloud storage, but I haven't found out how to do it. Using it as a dedicated ebook reader maybe the best idea I can do with it.
https://www.reddit.com/r/termux/comments/mkzoyd/showcase_ful...
It isn't that well supported in PostmarketOS (charging and OTG), but that sounds fairly fixable. Ideally you'd want both, then connect to a charger/ethernet combo.
You might be able to use the downstream kernel for that, or Termux on Android.