Jet Blue for me is the cashews...I'm about as bad airborne to cashews as I am peanuts. They smell stronger and worse for me too.
Sigh..yeah...so...I think getting banned off a flight depends what kind of accommodations are needed, if a general announcement needs to be made, who the flight crew is and if they have a personal vendetta against pa people, and who the gate crew are and if they have a vendetta against pa people.
I'm smell sensitive, and sure I'm uncomfortable, but a person or two with peanuts around me won't cascade me down into a big reaction. I might get a red face, but it's b/c I'm a bit anxious. I can get a bit stuffed up and eyes red/itchy (like someone who is allergic to cats, say...) but I've never had it progress. It went a little further once on a SW flight and I started getting hivey and a scratchy throat...but benedryl killed it. That got a little freaky though and I was anxious...so never SW again.
Point being - I don't have them make announcements...and if someone RIGHT in my row has something I'll speak up to them and tell them I am allergic and have to get up and I'll return when they are done. I bring them back a wet wipe usually. Once I moved my seat completely with the help of a flight attendant b/c the whole family was eating roasted peanuts. A nice person 10 rows back switched with me without griping