How to add a non http hosting and/or provider?

Is it possible for addressable build and upload and then download from a complex logic?

Such as json and text data. We could have custom database or ftp or an SDK to cloud database.
Not a conventional host : port or normal local filesystem

Addressable system seem too complex to easily plug things. I wish I could just right click => add provider => cs file generated extended from provider like a monobehaviour, and unity will registered our provider to its file system. Something like that

 

Yeah, I agree the package seems too complex... I think they tried to cover too many scenarios and they ended with an over complex solution, they should have started making small stable incremental changes.