The "is/was" styling could be adjusted slightly to make things clearer. For example, if one author in a relationship had passed away, then it should automatically say "was involved with" (e.g. Mark Fisher (https://bookbrainz.org/author/53e17219-9e46-4610-b263-f0d6deb6d510) passed away, so his relationship with Land and Plant should be in past tense). And in the cases of things like divorce, we can often find the year(s) they were together, so we should have an option like on MusicBrainz where we can enter the years they were married if they are known.