Alan, I found examples online from a grammar blogger that say your examples are the opposite of what they should be. If you have one wife named Diana, then her name is nonessential to understanding the sentence and requires commas. If you have one son named Scott, that also requires commas. If you have multiple sons, then his name is essential to understanding the sentence, so no commas.
That means, in my case, that the name of the epithet is essential to understanding the sentence as there are many epithets, so no comma.
I'll probably forget these rules in a week and start doing it wrong again.
Thanks
Dirk