My son is contact sensitive too (and had autism/aspergers). I have to admit, I worry a little-- not enough not to go though (first trip, we didn't even know he had a peanut allergy-- so we weren't cautious at all). I worry a little about Beaches and Cream because they cover some of the sundays in chopped peanuts and have alot of peanut butter sauces-- but we may still go there. We keep Benedryl (fast tabs-- the meltaway ones) and the EpiPen with us at all times.
The table services are nice because the Chef will come out and talk to you. But yeah I worry a little about what was eaten in his seat before him. However he went to a school this year where the kids ate PB&J in his class (the teacher just made sure the child next to him didn't have pb&J). He came home with some hives now and then, but was ok.
If I see a hive, I start the Benedryl (and he takes Zyrtec every day for environmental allergies)-- doc says doing both isn't a problem.