For example, an artist first releases his song on Patreon for patrons before later making it available for purchase on his website with no difference in regards to metadata. Should these be separate releases or only one release with the earliest release date set as the release date for the release while the release date for each individual website added to the date on the URL-Release relationship? I’m currently more inclined towards using the latter approach.
My opinion: Unless there is something different about the release (different track order, alternate versions, etc.) I’m inclined to have just one release. You can add as many (legal) download sites as you like.
There’s no consensus - if you have the time and find it useful to enter multiple, then enter multiple. Otherwise just add the links to one release.
I add separate releases if I find something notable, eg label release release some time after self release, different art, different bitrate etc
This is like releasing in more than one country. IMHO it should be a single release in the database, but multiple dates added to it. Each of the links then get added to the one release.
The physical item is the same - the same number of tracks, same music, same edit\mix. Just location is changing.