Jdk11 is working on kindle pw6 with firmware 5.17.1.0.4. And I just checked with other people in the discord, new firmware pike 5.18.4 also use old glibc. So I guess jdk11 is what I got now.

This device can't even run browser properly, so hopefully I can write something to call api and display me some info. Maybe in that case go is better than Java?