But you seem unable to acknowledge the fact that the “radio requirements” don’t guarantee that (1) radio is fitted and serviceable, (2) tuned to the correct frequency and (3) being talked at by someone who’s not making errors as to position.
Setting all that aside, you say that “virtually all that the higher speed Challengers, Dash 8s, Fokker etc will be flying into” these places. I suppose it depends somewhat on what your definition of “virtually” and “etc” means. Just to choose from a couple of recent close encounters: What flies in and out of Jacinth Ambrosio? Beverly Camp?
Why is it acceptably “safe” for the passengers on the aircraft that are the exceptions to your “virtually” and “etc” rules to be exposed to these risks?