I work at a high school that goes really deep in the playoffs every year.
During the regular season we have never had anyone come talk to me about it.
During playoffs we haven't had a ref come over during rounds 1-3.
Area Finals and on I have had refs come over every game. Most just said not to play if the other team is about to score right in front of us. Other than that they mostly allowed most bands to do whatever.
I have had one come over and tell us to go by the rules, and when I pointed out that the other band is doing it he agreed to go make them stop as well. No more issues.
The rule they mostly enforce is to not play after they break the huddle. Make shorties of all of your tunes.
Go to the UIL site that has the rules for playing and print it out. Take it with you to the game, and if they tell you something other than what is written then make it a point to talk to your athletic director and principal at the same time.
Read the NCAA rulebook (which UIL uses for football). Bands are not allowed to play once the center has addressed the ball. A ref has the right to throw a flag on your sideline EVERY TIME you go over. If the opposing coach wants to, they can make it a point to demand this penalty be enforced.
Shorten up your stand tunes. Use "Shorties" arrangements. Gone are the days of long songs except between quarters. Watch a college football game or two and see how they make it work. They've been doing it for years.
The world will go on. Teach your band the rules, teach your community the rules. Don't be the reason your team gets a sideline infraction.
Our students did amazing. We had the superintendent say its the best she's seen the band for a first game. Only problem was a ref told us we could not play on defense. We have a rule we don't play on offense only on defense. It kind of bummed my students out taking them out of the game for the 2nd half. End small rant. I hope everyone had a great long weekend.