I dont see why people have difficulty understanding the concept, the grip should be loose ( , but enough grip on the handle that it would not slip out of the hand) before impact and tighten at the point of impact. P.S. You need to use the correct grip for each shot before playing around with how soft the racket should be held
I am aware of the comment when I watched the video a year ago. Exactly what motivated zhao to say this I don't know. Sometimes you are forced to panhandle if the shuttle is far infront of you like a net kill. The videos, excellent as they are, are semi casual conversations with various badminton players and the coaches they are not the gospel. The fact is basic grip for overhead shots is essential otherwise your progress will be limited. Above a certain level there is absolutely no player who panhandles smashes or clears. The sooner you change to correct grip the better otherwise it becomes much harder to change.