I see why you want this.

I'm imagining a parallel-to-nostr protocol that is also over websockets, can deal with chunking (to handle the websocket frame size issue), is binary (to speed the transfer), handles compression (like HTTP, probably via HTTP actually), specifies commands to edit/update data, has some kind of auth but still uses nostr pubkeys. Something like WebDAV but way cleaner and designed for nostr identities.

I think the amount of work to do this would only be 20% more than trying to do it over nostr, because you wouldn't be duplicating very much of what nostr is, and a lot of code used for nostr could be repurposed.

Just an idea.