It would be a sad lookout for 17(R) Sqn doing F-35 Operational Test if the most they ever do is draw a straight line from the ship to the target at 35k and back again! Just because you're in a stealthy jet doesn't mean you should ignore all the known SAM sites, fly round them if you can! Stealth is just another tool to help the pilot survive and successfully complete his mission.
With the jets at Nellis now I'm sure the USAF are working out how best to employ them in various scenarios. If low level fits the mission profile then great, if not, why stress the airframe?
We might have to wait a few years until an F-35B goes through the Mach Loop!