Help from knowledgeable Bench rest Silhouette shooters

[Panhandle]

Reading the rules it appears that a tuner/sight extension tube is allowed. They aren't a compensator or muzzle break, Correct ?

Secondly is there a sound reason Spotters are not allowed? It seems contrary to every other flavor of our sport and prohibits the opportunity to develop relationships. Spotters allow none shooters an opportunity to participate, develop relationships, build shooting related skills and enhance safety.