Contact them direct with issues as serious as allergies.
We have found them to be excellent with allergy info, mine aren`t life threatening, but they still take them seriously. In restaurants, chefs will come out to talk to you if they need to or if you wish them to.
One of my friends has 3 kids all with serious allergies and they always contact Universal directly before leaving and speak to individual restaurants.
So, they absolutely are allergy friendly in our experience.