It's of course all a crap shoot and dependent on the whim of the individual officer. The letters aren't "required," just "strongly recommended."

In this instance, the thought did cross my mind that the officer in question would have looked forward to chewing us out in front of our grandchildren if we didn't have a letter, and then sending us on our way with a stern warning that we should never let this happen again, saving us a couple of minutes watching him read through the letters laboriously.

OTOH I too have seen officialdom in action and if we had invited this particular agent (and a few others I've encountered) to participate in a Facetime session with whoever was on the other end, I don't think the result would have been pretty.