Using Parameters in Curvature Adjustments section you can change the curvature of the normal, for example make it look inwards…
Here some results made using this shader:
Pay attention that if you have a circular shape with a propper UV’s then you can get rid from “remove unwanted” section and save some instructions. Also linear radial gradient calculated using distance node can be used instead, but personally I like it more without the sqrt (Commented as Radial Gradient Mask).