I got an email from a reader a few months ago. My reply got a little long and off-topic to what the reader had asked about. So I'm posting here and will email a copy to the reader too. The actual question is, I think, easy enough to guess and not terribly necessary to understand my response.
This is a companion discussion topic for the original entry at https://jlericson.com/2020/07/08/reader_mail.html