Yup it’s the cross contamination that’s the killer.

It would be a nigh-on 99% “treatment” if coeliacs could tolerate tiny amounts of gluten, as it would allow you to just say “swap these ingredients”. Instead you enter a restaurant and you have to have a deep interrogation on how their kitchen functions; what goes where, bla bla. And if I have to explain, even one more time, that gluten doesn’t “burn off in an oven” I’ll scream.