I'll endure the weight of a mounted spare for our Class C. Heavy but right where I can still handle it. If it was 19.5" or bigger, not so sure.
I looked up AAA Road Service and they will "install an inflated serviceable spare" which makes it clear to me that at least AAA will not break down a flat, mount and inflate a tire for you.
I tried to find this out about GS and CoachNet. From Comments, I couldn't tell. What I did read, was BOTH have sent "road service" out without what they needed to change a flat. No JACK in one case.
So, My Story and I'm Stickin' To It: Carry Mounted, Inflated (meaning check it once in awhile!) Spare, and at least a Jack and a Wrench. I'm sure it "costs" a hundred pounds, but worth it to me.