Excellent answer ... thanks.
I was working chrono at a match last weekend and found a competitor with SA/DA gun in production where the safety didn't work. He said "show me in the rule book where is says it has to". I did refer to 5.1.6, but it doesn't explicitly say the safety has to work, although I suspected it did.
I didn't have the equipment check manual handy, nor did I think to look there, but that is the right answer