I know lots of people here have had problems using Calibre and plugins to manage their Kindle library. Most of us want to host as much as we can locally without relying on cloud services and Amazon doesn't provide the tools to do that efficiently. Whether or not you use a Kindle, as a market leader they set a certain standard that other readers use as a baseline. Towards the end of convincing Amazon to give users better tools to organize and manage their library collection I have started a thread on the Kindle forum and I would appreciate it if some like minded people would contribute!
https://www.amazonforum.com/forums/d...-books-oasis-2
As these are issues users have had with Kindles and other publisher supported ebook readers I have no illusion that we will win this battle with an update tomorrow but I do believe it is important to be persistent.