On our first visit, we explained to the waitress that we had a gluten allergy, which meant needing to avoid wheat, wheat flour, and soy sauce. The waitress was able to show us on the ordering tablet that the different options show their ingredients - and while some were in Chinese instead of English, she showed us what the Chinese for wheat was. Most of the soup bases, and many of the hot pot options (basically everything except the obvious noodles and such) were gluten free. While many hot pot restaurants only have a plain water or veggie broth that's gluten-free, the tomato, tom yum, and bone broth at Haidilao were all safe (and all DELICIOUS).
We've now been multiple times, without any issues of cross-contamination. The self-service bar for additives to your personal plate is as dangerous as any salad bar, but they do mark which of the options there are gluten free. And you can always bring your own mix-ins if you want (like minced garlic, tamari soy sauce, sesame oil, etc).
The service has been great every time we've gone, and if not for the price, we'd go more often.
— Somewhat
— Gluten-free items are marked on the main menu
— Most/All
— Excellent