The goal of the `\b` here (but I now realize it was borked anyway) was to avoid matching things in the middle of a string, like say `<lala("foo@test.com")>` would now match a `@test.com` reference in the middle and break the whole thing.

I think the boundaries should be added back but with a more sensible `(?:^|\b| ?, ?)` and `(?:\b|$)`. I think this should work to allow multiple while preventing conflicts.