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No. You would need to have a system wide content blocker like AdGuard for macOS as opposed to an extension only.

Extension support​

Now you can personalize web apps on Mac with Safari Web Extensions and Content Blockers. Navigate to the web app’s Settings menu to access all your installed Content Blockers and Web Extensions. Any enabled in Safari will be on by default in the web app. Each web app is uniquely customizable, just like Safari profiles.
 
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