Just so you know, @NEETzsche there has been a tiny misunderstanding. Backend code is a bit of a mess in that part, so I assumed "scrobble" creates a type: "Create" with document "Audio" with url assigned, but it does create a "Listen" to an "Audio" with given url/metadata.

The real problem is in "Audio" it is referencing - even though from ActivityPub perspective nothing matters and you can "Arrive" at nonexistent "Place", much like "Audio" doesn't have to be created in order to be listened to, we do ingest type "Audio" from funkwhale, so we have inconsistency between type "Audio" that we receive from funkwhale, and "Audio" that we make up in "Listen". For now I think we are the only ones who support "Listen" at all, funkwhale doesn't support it, however if they or anyone else DO add support for it we'll have a problem - if we receive a "Listen" we have to figure out if it's a "Listen" for a "real" "Audio" i.e. actual Audio document we ingested from funkwhale or it's a made-up nonsense "Audio" from (older) Pleroma. This is what you've been calling a "non-issue" and I do think that IS an actual issue that needs to be addressed, and I've started addressing it already.