Free write is much easier and less time consuming to create if you are an expert. I don't think everybody can produce contents straightly from their head unless they are much experienced as you. You have a lot of knowledge and experience gathered from your long professional life which inturns help you in freely writing them down. And 4 quality articles a day! Incredible!

And trying to write freely indeed allows us to research the topic we handle further. Anyway, it nurtures creativity and allows us to understand ourselves more deeply.