I got a Boox Go Color 7 as a less locked in alternative to my Kindle a while back, and overall I've really enjoyed it.
It's apparently rootable, although I haven't done that personally. It's Google Play certified so anything from the Play store works, and side loading Android apps works too. I use it with the open source KOReader app and in tandem with Calibre Web Automated. I did a writeup[0] with some details if you're interested.
I second this, been using an Onyx Boox tablet for a year and a half for uni. It's great for reading and taking notes and it fits nicely in my laptop bag on top of my laptop.
It's apparently rootable, although I haven't done that personally. It's Google Play certified so anything from the Play store works, and side loading Android apps works too. I use it with the open source KOReader app and in tandem with Calibre Web Automated. I did a writeup[0] with some details if you're interested.
[0] https://blog.eldrid.ge/2025/03/12/self-hosted-ebook-manageme...