I haven’t personally investigated... and I’m not sure how one would go about it, given how, at least without GDPR, I suspect more and more confirmation of analytics data between parties will happen server-side for performance reasons. Of all third-party content, SaaS and font networks would already have to track everyone with unique IDs if invoicing based on usage, but it’s damning if your paid service provider says it collects and shares data (presumably about your users) with advertising companies in the privacy policy. As if they aren’t making enough money from you? Or maybe it’s to support tiers of service?