I've done it with the stock grate without any issues, but the 1 time I made chili in a dutch oven with the gourmet grate it warped and dropped in the middle and never was the same. Seems counter intuitive since the gourmet grate is thicker and is made to hold that Cast Iron Wok, but I just don't think the 2 piece design is as structurally sound.
The good news is I had just bought the grate, and Weber replaced it with no issues whatsoever.