That part stuck out to me as well. However, I wonder if that would be as conclusive as it seems. Even if waste removal is faster while awake, waste creation may

That part stuck out to me as well. However, I wonder if that would be as conclusive as it seems. Even if waste removal is faster while awake, waste creation may be slower. Part of the purpose of sleep and getting tired could be that waste concentration hits some threshold, and the body says “it’s time to stop creating so much metabolic waste”.