I jailbreaked my Kindle Paperwhite 3 running 5.6.5 using theese
instructions , specifically in hopes of using CoolReader. I've been looking around this website for a little while now, as well as the web in general and besides
this, I have found nothing that says anything about PW3 on the tin. For example the paperwhite and touch
instructions for CoolReader tell you to follow instructions for
K5 Collections Manger. That has NOTHING on PW3. Same with
MKK, which everything seems to require. So what's up with this? Is this reader super unpopular so nobody makes stuff for it, or what?

Actually, I just realised that MKK Comes with the jailbreak, so that part's ok.