Have you asked your service center if you could borrow a loaner with a different interior for a few days to see if the issues go away? (sorry if I missed if this step had already been tried).
The ultra-white seats are made from some form of plastic, possibly PVC. Have you had issues with PVC in the past?
I've done several, 2 paid Turo rentals (one after returning a brand new X 100D loaner that was intolerable). Both were GREAT, although one owner needed to do some maintenance)..
Before buying my X I convinced my mother to buy a model S (this X is my second Tesla). I wanted to have same AP version and everything as her.. She has a few problems and had a few loaners also -- All great (will one had bars you could kind of feel in seats, but no allergy). Also did an overnight test drive in a X and it was a GREAT car.
All I want at the end of the day is a car that matches what I test drove, no allergies, nothing different that caused me problems..
I'm leaning towards just going back to other brands, my S is awesome but it's pre AP.. At the end of the day I just need something that gets me from point A to B, and if that's all a car can be then so be it, if it can't handle that task then looking cool and fast is useless.
I'll probably have mine sold this weekend, Tesla says no leather P100Ds but there's one in the showroom, in site, as they are explaining that - My opinion of their cars and their honesty is down the toilet with that, if you can't tell the truth then I don't want to do business with you, I'll support an honest company.