most powdercoated items (pellet grills, stoves, ect...) are good for up to about 600* \
anything your grill can do should not hurt it
I had a Traeger Jr. with the old (non digital) controller,
it would run 500-550 easily,
and I saw 600*+ several times when running it wide open using LumberJack Charred hickory pellets
the paint/powdercoat on it was definitely suffering
as was the firepot