Chevron defense is separate and distinct from Auer defense. The Chevron defense applies to Congressional legislation, Auer is applied to an agency's own vague regulations. I have no issue with restricting the Auer defense. If an agency issues vague regulations, then that's their own fault. You're correct that they're both being attacked, but the underlying issue won't go away; Congress can't/won't dictate every detail of legislation especially when it comes to general/vague legislation. They have neither the inclination nor domain knowledge to do so.