If you are into self hosting there is a very good tachiyomi plugin for Komga which is a manga and comics server you can self host and fill with your own content, it also supports connecting to multiple servers.
I have 2 Komga instances running on my home server (one for normal manga and one for the.. other kind), content is collected by FMD2 which automatically downloads series I have set to monitor (similar to sonarr but less polished). then in tachiyomi I have access to all of that content streamed across the web to my phone and boox e-reader anywhere in the world. it's pretty neat but the only missing feature is synchronising read status and position across devices.