WKContentRuleList Ability To Apply "css-display-none" to an entire style sheet dynamically?

I see in the documentation that it is possible to hide elements on a page using a CSS selector by setting the action type to css-display-none and then providing a selector.

But this is kind of limited. You have to know every selector for every style sheet ahead of time. It's possible to block loading of a style sheet using a block rule.

"trigger" : {
      "load-type" : [
        "third-party"
      ],
      "url-filter" : "REGEX_FOR_STYLESHEET_OF_KNOWN_NASTY_CONTENT_PROVIDER",
      "resource-type" : [
        "style-sheet"
      ],
      "url-filter-is-case-sensitive" : true
    },
    "action" : {
      "type" : "block"
    }

Is is my understanding that the above rule will block loading of a stylesheet that matches the url-filter but all elements will still be displayed by WKWebView using the default style provided by the browser. Am I misunderstanding?

Ideally I'd like to be able to set display:none; for every selector in the evil style sheet. I of course can look at the style sheet and make css-display-none rules for every selector manually but that's pretty much impossible to maintain for rule lists with thousands of entires and will break when the author of the nasty stylesheet makes any changes.

Is there a way to accomplish what I'm after using WKContentRuleList?