You have two options to making a less chewy/tough pizza upon standing. 1: Change to a lower protein content flour if you can. For example, if your present flour has 13% protein content, going to a 12% protein content flour will help to reduce some of the toughness. 2: Continue using your existing flour and increase the fat content. Right off the bat, I'd take it up to at least 5% of the total flour weight and bench mark from there. Maximum tenderness is achieves at around 8% total fat content. You can go higher, but you begin to compromise other characteristics. If you really want to see how the fat level influences toughness, just buy two packages of tortillas (not too terribly different from pizza skins), make one a "feature" package, while the other should be a "normal", full fat tortilla, you don't need to fill and roll, just heat and eat and you'll immediately see the difference.
Tom Lehmann/The Dough Doctor