Yes, you could write a proxy auto-config file[1], host it somewhere and have it rewrite the urls you want. I think that's how an ad-blocker worked on iOS befor

Yes, you could write a proxy auto-config file[1], host it somewhere and have it rewrite the urls you want. I think that's how an ad-blocker worked on iOS before they enabled the functionality. [1] https://en.wikipedia.org/wiki/Proxy_auto-config https://en.wikipedia.org/wiki/Proxy_auto-config