I've heard about Kavita and CWA. Kavita can't fetch metadata sadly and it has too much behind the "+" service and CWA, as far as I know, is not very good for managing Manga and Comic.

Any recommendations? I would prefer it to be able to get it on the same app so I don't have to constantly change IP on Kindle.

UPDATE: if you take the Komga & Komf route, use Komga 1.24.4 and Komf 1.7.1. Looks like newer releases of both just don't work for some unholy reason.