I have stopped at the allergy kiosk multiple times and have found it very helpful. They have an Ipad now with the allergy menus from all the restaurants in the park. The cast member at the kiosk said we still needed to check with the chef/manager when ordering to ensure accuracy and special handling. We were able to look at several different menus and decide which would work best without walking back and forth between the restaurants. It also made ordering at the restaurant much faster. When the manager at Flame Tree arrived to take our order we told her what we had already decided on and she confirmed that it was safe. It took less than half the time it normally does to order.
The snacks are a great deal! The pint of Tofutti was cheaper there than at the local grocery store and a better deal that they regular ice cream in the parks.
I would highly recommend you stop by there at least once. Friendly helpful cast members, nice snacks that are different from the typical park food and it could potentially save you a lot of time and effort.
If you do use the kiosk stop by guest services on your way out of the park and request kiosks in the other park. I was told that there was talk of it but no plans yet and the guest feedback was a big help.