For our GPU temperature testing, we measure the peak GPU core temperature under load. A reading under load comes from running Cyberpunk 2077 for 30 minutes.
Given both cards use the same cooler and heatsink design, it's not a surprise to see similar thermal performance between the 4070 and 4070 Super. The Super does run a couple of degrees hotter, though I think that's to be expected considering it has a higher core count, and therefore higher power demands.