Right now there's a discussion if we shift that data over to nostr, or if it gets POSTed to server the podcaster or their host controls. metaBoost is the current proposal I'm most behind. https://github.com/Podcastindex-org/podcast-namespace/discussions/676

My 2 cents, send it to the podcaster's server, and if they want to post it on nostr, they can have a function that takes care of that. But there's a lot going on, like keeping track of how many sats were sent and the time sent that the podcaster is going to want to keep track of for potential tax reasons, so they'll want to store all of that data in their own data base.

Not saying signing a nostr note and sending it via relay isn't viable, but converting the JSON to a flat array, signing the note, etc is part of the discussion of how metadata should be handled.