You could do all the fancy hashing and cdn lookups but i think thats still overcomplicated. There's no need to push the metadata or file hosting onto relays. All the relays need is the guid of the feed (its in plaintext, can't miss it) and the apps just need a library or template or git so it knows how to decode the tags. But I digress... it's self hosted and thats the key.

If you want it distributed, put it on a blossom server and literally ctrl+v that in your RSS (a text file). Done.