Is there a valid reason to carry the extra weight of spare tire? Will roadside assistance show up with tire mounted to wheel and then change it? There is no way I could change it myself.
When we bought our used Class A, at 8 years old, it had a spare wheel, with tire, mounted under the propane tank with a chain and padlock. The seller said he'd never unlocked it, since it was installed so you could get to the inflation valve quite easily.
When we sold the rig four years later, neither had we! We did replace all six road tires because of age when we bought the MH - they were the OEM originals from the chassis build date.