Could this not be solved by by Grindr setting up CORS properly for that resource? It's unlikely anyone would ever open the script directly in their browser.
CORS wouldn't help here. CORS prevents you from reading the response or making a cross origin XHR requests, not loading an external resource from a different domain in a script or img tag.
Fun fact: browsers put scary warnings in their dev console (and some web sites log warnings or console) because some people love copy-pasting code they got from sketchy people trying to bypass all the browser security.