Can JS really block requests to a server or is it more ad hiding than blocking? I suppose WKUserScriptInjectionTimeAtDocomentStart could be used to inject somet

Can JS really block requests to a server or is it more ad hiding than blocking? I suppose WKUserScriptInjectionTimeAtDocomentStart could be used to inject something that will e.g remove ad-related DOM nodes, although this is more theoretical than a reality I guess. UIWebView can drop connections based on URL matches and also content analysis OTOH, and that's a pretty well understood way of doing things. One more plus for WkWebView that I forgot - the history list and moving backwards/forwards in it. I agree it has some really nice pluses, but at least for my use cases (and the use cases I would be interested to see implemented in iFirefox) it doesn't seem to be the right choice.