I believe the NFHS Lack of Action rule was deleted sometime after 1990-91. I graduated high school in 1991 and during our district ifnal game, the other team decided to wait for the last shot in the first quarter and was given a warning for lack of action, before hitting a buzzer-beating bucket to tie the game.
Fast forward to May 1994. AAU boys tournament with modified NFHS rules. one of the team decides to stall when the other team goes zone, and the referees aren't counting for lack of action.
So the rule was apparently deleted between 1991 and 1993.