Rating fitness and alertness

I am a heavy user of Sleep As Android for several years already. Every morning I rate my sleep, but I honestly don’t know why. In the morning I tend to be groggy and if I think I had a long night I got the 4 star button.

Wouldn’t it be better if there is an option (or plugin) available that asks me three times a day how fit and alert I am? By doing so I can better correlate my fitness (which is the real goal of sleep in my opinion) with the amount of hours and quality of sleep…

Hope someone can develop such a feature.