If he has a 2014 toyhauler he most likely has wheels that will handle 110 psi rated tires. He can look on the outside of the rim and generally find the rating. I have Sailun tires and am very happy with them. I know nothing about Kenda.
From what I can see with that device, it won't do anything to prevent the tire from coming apart, but it will help keep the beads near the rim edge to prevent the tire from folding over. It wouldn't have done anything to help with the 2 blowouts I had since the beads on both tires were still in place. Not anything I would spend any money on.