@moth4017
It didn't show a difference for my recent prints, both have quite nice first layer. However those are small prints at the center of the bed. My printer is a small one the bed is 230x150, and seems pretty flat from height map, I had been watching but never found any movement of Z when it prints first layer with height map enabled.
Actually for most prints the first layer is good enough, the difference is fine vs perfect only for large print. I guess the inconsistent comes from the whole system. I see videos of the Bambulab printer does pretty long calibration for every print, and it vibrates a lot when calibrating. Maybe that vibration not only helps input shaping but also help the whole mechanical system to settle down to the same state.
Thank you for the input! And btw, the spamming system of this forum stops me from posting or replying or editing twice in the same day, I have to wait a day or two to reply....