I have seen that you are visiting Spain, we could meet and have a beer 🤣🤣

Now as for NIP98. It would be as easy as authenticating on each server separately no? What you describe is something very necessary to manage authorization events, which avoids reusing an authorization event (intercepted) to authenticate on another server

NIP96 now allows to list files as well, and the spec in its essence allows to upload files to several servers at once. There is an event (kind 10096) to publish the list servers.

I don't really have anything against blossom, but I want to understand it well before I make a decision