ok I see, shame that the media manager cannot be easily extended as the rest of the core. I probably know how it works more than me with all the great work you already did.
My main concern is that I'm think about a plugin that would allow to edit content on frontend (something like content editor), but with the ability to deal with media. In a perfect world, I would like to open the media manager on frontend to pick an image. If it can work with your module that allow to directly search with popular data banks + resize / crop etc... provided by the external plugin, it would be awesome
frontend editor, for example like froala toolbar or something like that, is a way too complicated, because of many differencies. for example, rainlab.pages plugin that creates file based content, rainlab.blog plugin, that stores posts in database, etc. etc. etc.
but i have an idea in my mind a long time... just... i need to focus currently on this