>after it is no longer under load This is irrelevant entirely, as long as it stays in the desired/designed range. More importantly the higher thermal capacity

>after it is no longer under load This is irrelevant entirely, as long as it stays in the desired/designed range. More importantly the higher thermal capacity allows for easier short turbo boosts which most of the load is. For sustained load, it matters only the hottest part (cores) of the cpu and water cooling is a lot better to transfer heat away.