Here is what I do (speaking ASA; NFHS is a different matter)
If the uni is designed for the jersey to be out, I ignore it.
If the uni should have the jersey tucked in, and
a) It is championship play or other tournament where we are so instructed by the UIC, I enforce it.
b) Otherwise, I ignore it.
OK, my name is Tom, and I have fashion-police phobia.
