I have tried several variations, as far as setup goes, but my goal is pretty straightforward:
I use the origin tag to track the origin of a track, a link to the album in the Qobuz web store, in this case:
https://www.qobuz.com/us-en/album/revolver-the-beatles/0060254767013Then I setup the customize web link via the Track Information panel settings (to your point, you can also view/edit the custom web link list via preferences -> Internet):
name="Origin"
web-link=<Origin>
I then check the "show web links:" option for "Origin" on the Track Information panel settings form, save and attempt to open the link from the track information panel.
That's it...
Of note:
- I can see the origin tag in the tag editor when an individual track is selected as well.
- I use the field to help determine the source of a track - Qobuz, HDTracks, whatever... Hopefully, I am using it as intented.