[redstone1127]

In high school if taking a knee referee should be informed first by head coach, then officials advise players. All O line except center should be in two point or standing. All Dline should be standing as well.
No head coach would inform the officials then try to run a play or he would pay the price in the future.
That said kids are so unpredictable. A lot of the time they don't even know what they are going to do, then can't explain why afterwards.
To control emotions most good officials have the lines standing so there's no scuffles or contact.
No reason for anyone to get hurt.
It's a hard thing to get hurt bad and not be able to play. Trust me we know.