You're right that it's more complicated with Real User Monitoring, and not everything can be done inside our Worker. However, we bundle the content of the RUM s

You're right that it's more complicated with Real User Monitoring, and not everything can be done inside our Worker. However, we bundle the content of the RUM script with our response (saving the browser another request), and we make sure it actually arrives only to, let's say, 1% of your traffic, or never to those on 3G. With GTM, Segment, or any other client-side third party manager this would be impossible because the rules evaluation is done in the browser. I don't really recommend running a RUM script for _all_ of your traffic - IMHO it misses the point of giving your users a better experience.