At the suggestion of johnk42, I got Anton's excellent (and free) "Mandatory Confirmation" mod that works extremely well: https://www.boonex.com/m/Mandatory_Confirmation
It would be really nice to add a "Resend confirmation email" link to the error message generated when an unconfirmed member attempts to log in.
My search for how to to do that turned up an unanswered request for the same information from more than nine years ago. Plenty of posts on how to put language key in HTML, but no others that I could find on being able to put HTML in language key.
If this is possible, would you please share the information on how to accomplish?