One commenter on here stated that the "new" crop of "drivers" have trouble reading English. TRUE statement! They don't come equipped with the common courtesy shown in past years.
Another wrote that insurance companies don't encourage the use of "flashing" due to implications if involved with a traffic incident. True statement.
After 55 years of driving everything from semis, busses, fire engines, ambulances, and cop cars, not everyone is going to act as you might want them to. Use your best judgment in the situation.
Personally, I flash drivers over, maintain a large following distance, and if the need arises--stop to help a fellow RVer in distress.