At my work (The New York Public Library), we created a “Google Analytics Proxy” that receives requests and then proxies them to Google’s Measurement Protocol so you still get the benefit of using Google Analytics but can control exactly what’s sent/saved in real-time.
It’s intended as a mostly drop-in replacement for the GA analytics.js API and to be used as an AWS Lambda.
You can check it out here:
https://github.com/NYPL/google-analytics-proxy