A quick follow-up here, @mentalstring. @david has a PR in the works with a completely differect approach here, that is looking very promising:
https://github.com/discourse/discourse/pull/25664
We should be able to merge this in core shortly and test it out very soon. It promises to solve all sorts of CSP issues with ad management software (and script management tools like GTM). It might not affect AdSense impressions though, that seems to be a different issue.