NSF is not mandatory for most states whilst catering (check your local regs). Brick and mortar and serving to the public, yes, you will need NSF to be legit.
Peace and Smoke,
My Weapons: Custom rig - Kandi, UDS; Bubba Keg; 22.5 WSM x 2; 18.5 WSM; BWS extended party; BWS Gator and an Onyx Oven; 29' ft Coachmen Leprechaun (Lola).
Dan Chambers get well soon, so we can tell you to "Shut up Chambers"