I answered that we have given you and answer but you obstinately refuse to accept it.
Just a thought, but JUST MAYBE your answer, and those provided, weren't as clear, as convincing, persuading, as clearly explained or as potentially consistently deliverable as you intended, require or thought them to be. Considering all the variables that have to line up (ball boys skills, LTG Chain movement, substitutions by either/both teams, unique unanticipated situations) does it sound reasonable that a finite, consistently recognizable declaration of the RFP might reduce the possibility of inconsistent, unanticipated confusion, better than expecting 22 teenagers to be consistently focusing, and interpreting the same specific behavior of the Umpire, many won't be anywhere near?
Blowing a whistle to affirm something important just happened, seems a far more prudent, positive, inexpensive precaution to minimize unanticipated confusion than presuming EVERYBODY will ALWAYS be properly focused on exactly where they are supposed to be concentrating, at the right time.