1. What should the new figures be, and why?
2. Does this actually affect the merit of the argument being made in the FAQ? (It doesn't)
1. The new figures should reflect accuracy on the part of current cruising altitudes for commercial airliners. While a 'typical' cruising altitude might be 36,000ft, as I said previously, commercial aircraft can and do cruise at altitudes of up to 45,000ft, depending on the airframe. The Concorde (obviously no longer in service) reached up to 60,000ft.
2. It affects the merit of the argument being made only in that the "hint" of curvature (in my experience) cannot be seen at 40,000ft. According to pilots of high altitude military aircraft, namely the U-2 and SR-71, curvature is visible upwards of 60,000ft.