My understanding is the undulations (for noise attenuations) are on trailing edges (owls wings) etc but on leading edges as per whales for allowing high angles of attack which are then less likely to stall.
The FACT these are found in nature developed over millions of years is most humbling IMHO.
Flowers giving off UV reliant colours for various birds and insects to exclusively see is another wonder.

Just watched this, was I seeing things or were the undulations on the leading edge of some of the wings and blades? I had it in my head this was a trailing edge thing.

Interesting developments. Keith Oakleys rudders on his quiet hovercraft displayed similar irregular
surfaces.

https://youtu.be/WezeLNC32sA?si=gyt5fgkaBONdBB8X