Ian,
The approach I use is to use the first name plus the first letter of the surname as the keyword in LR. Then I would add synonyms for the full name and any subsequent names.
So I understand you would tag the name applicable at the time to a photo (e.g. Mary Smith, Mary Jones) but would use Mary-S as your search criteria and it would find all of them because you've set them up as synonyms?
However this will not make it easy for you to isolate all photos of Mary between the ages of 25 and 45 when she was Mary Jones. So another approach would be a hierarchy:
I assume this is because iif you searched on any of the names set up as synonyms it would find all of them? In other words, LR does not support one-way synonyms?
The hierarchy by first name is an interesting concept. The difficulty I see with that is that it doesn't fit well into a family/work hierarchy. It would seem to have to be either/or. I'll have to think about that one a bit.
Thanks for your thoughts.
Dale