Right now as far as I know we can only import(copy) specific files/folders from the cloud/other remote location to the on-device library. But what if we could index some of those instead, as a part of the bigger library?
I feel like many of us have a large library on their PC/NAS, much larger than iOS device free space allows, and would love the ability to see everything we have (with our current reading progress) to chose what next to read via the same great UI with posters that Panels provides. I think you could do a remote library approach similar to what comiXology, Plex or Infuse feels like.
You could allow to add whole remote folders (SMB, WebDAV, some cloud storage, etc) to the library, store and sync its collection/folder structure with posters, reading states, and the folder connection data in the app.
The “cloud with arrow” icon could show if something is on a remote server or downloaded to the device, with downloading possible if the remote device is accessible.
And a toggle between the whole library/on device view will be useful then.
I understand that this solution would usually work better if there’s a web server installed with a library database and access to the files. From reading the forums I know about Ubooquity and Komga support, but I didn’t try those yet. But I think the app-focused solution could work great too. I think Infuse for iOS would be the best example of the idea I propose - it stores the library database/metadata with everything indexed and links to remote storage etc in the app and the cloud, and syncs it between iOS/tvOS devices. It scans any new location added, generates metadata like names and posters, and updates it occasionally. This way you can see everything you have at any time, while downloading only what you need by small portions as you progress through the chapters. And you also could support auto-downloading N next chapters when you start something, and maybe “streaming” with seamlessly preloading next images while opening remote comics.