Laundry is in the Moorea building, first floor. We haven't used laundry at Poly, so I have no personal experience with it.
Across Disney property, with mobile order "some" things are customizable (like saying no onions or no sour cream...but if it comes in a separate cup, they may give it to you...got sour cream at Pecos bill in a cup despite saying no sour cream.) You can do a practice order from home when the restaurant is open to see which items are customizable and just don't pay. There is also an allergy section after the drinks category on mobile order so it'll bring up some menu items they can make for that allergy.