Noticed a bug on zig zag curve creation. We see zig zags on flat surfaces but not on any curved surfaces as shown in your video examples. We have tried with step and igs. Also extracted the curved surfaces and imported those as step to test.
Which video are you referring to?
The zig-zag automatic extraction you are referring to may not work well for curved surfaces.
It may be better to export your part with the curve, use a sketch, a plugin, CAM software or define your curve manually.
If you can share your sample part we may be able to help you better.