Go for it, I think you will be pleased with the outcome. We usually use 3/4" or 1" angle for the frame on larger grates but recently made a set for my son's cooker approximately 26"X22" and used 1/2" square tubing for the frame; they are plenty strong. The expanded metal also seasons up great.
Weber 26.75 OTG w/CI grates & SJ/WSM Mini
Home built 24"x72" reverse flow stick burner trailer with 18"x44" grill w/CI grates and upright SS gas oven/smoker.
Home built 48" fire pit with a 30"x30" Santa Maria style ranch grill.
Home built lump charcoal retort, iGrill & a bunch of other cooking toys.