全部禁用后建议图标变成灰色，或者加一个划线，以提高辨别度

It could kill HTTP Header Mangler, Redirector, url-redirector, Skip Redirect and NeatURL, but hopefully it'll have a user-friendly way to achieve what now 'custom function' feature could do; Material Design; And the authors seem to be steadfast GPL supporters.

BTW, can it delete a header?

Very well designed.
Providing a dropdown list of all available headers would be even better.