[innocenat]

> What about battery replacement?

I don't think any e-readers are designed to be user-replaceable except the very first Kindle. As for DIY replacement, I don't really know, sorry.

> A replacement battery manufactured shortly after the reader is going to be as bad as the one that came installed by the time I need it.

Is it? I was under impression that battery mostly degrade with cycle count. At least, there are plenty of people still use Kindle from 10 years ago.

> [...] warranty replacement is a solution.

Then I think you are mostly limited to Kindle or Kobo. Most other e-reader or e-ink tablet are mostly shipped from China so warranty and replacement are going to not be as good.