it may or may not be a concern. On one of my keggles the valve is right over a cut out on the skirt. A lot of heat comes through there but the valve has never failed. If there were flames coming out of the hole, that would be another story.
Regardless, I have on occasion fashioned a shield out of several aluminum foil. Folding it in half 2-3 times and placing it under the valve. It did keep the valve cooler.
Good luck in your efforts.