nostr:npub13430fh0ez029munmajpzze97rztux82rpxc39t8hxc5gywdptz4sltsaj4 I got a Kindle Paperwhite of the 10th gen specifically to jailbreak it (I followed the mobiread forums and got one on ebay, when a new jailbreak was out). 
I installed https://koreader.rocks and it's a great reading experience - even if I would not care about privacy and being free of DRM, koreader is just excellent. 

(I got that Kindle for being waterproofed and robust, and it's likely my longest surviving eInk device now, despite being with me constantly for over 4 years.)