Thanks for the clarification

Could you please explain what Kopub is? I cannot find information online: is it a jailbreak method? an app that can be installed after jailbreak? Do you have a link?

I’m on the same boat as you (except on a pretty old Kindle Touch), and I still don’t know if it’s worth for me. It seems like people will lose the ability to connect to Amazon’s servers and will lose the books they bought from them.

But for us who don’t get our books from Amazon and just transfer them using Calibre: are there any big advantages?