I don't know. It depends on your flexibility. I'm really inflexible, always have been Even in high school, stretching before track meets trying to touch my toes. I could never get closer than mid calf. Other guys could touch their easily, even put both hands flat on the ground. Not me! So, FOR ME, I need to roll my pelvis forward and ride with a pretty much straight back, rather than bending at the waist. This means I need a "wave" saddle, rather than flat.

But that's me. If you're more flexible, you can curve the whole back. Cam Nicholls has a series of bike fitting videos, I think on the Road Cycling Academy YouTube channel. You might find them helpful.

Or confusing.