It seems every partition except cache(?) need to be backuped. Otherwise it will encounter the bootloop and in fact this is what I encountered. I only backup the data, boot and super partition in TWRP backup function.
I don't understand what's the meaning of 'everything you can see on the PC...
It seems the changelogs are all published on an app called coolapk which orginally was a third party android app store based in mainland China. https://www.coolapk.com/feed/36912330