Hah! Nice catch there :) This is actually not part of the core Makeswift code, but a custom snippet we added to this blog post to tweak the navigation. It sets

Hah! Nice catch there :) This is actually not part of the core Makeswift code, but a custom snippet we added to this blog post to tweak the navigation. It sets a class on scroll, which is why you saw so many errors in the console. I just fixed it. Thanks for letting us know!