If you scroll up I made an argument for writing out a spec sheet for the fields you merged some years ago in the interest of interoperability (taking advantage of Elixir’s polymorphism), but it’s not really pertinent to the outstanding MR: https://git.pleroma.social/pleroma/pleroma/-/merge_requests/3977
The outstanding MR is about adding a user-defined url to the scrobbles endpoint, which allows you to do things like this in the FE. (If you click the YouTube link it takes you to the YouTube video)