All websites should be treated differently. Due to the increase in technological dimensions, and massive javascript. It is difficult to treat all equally
Because of the present preloading of site and broad javascript, it's difficult to make a content/bot which treats all URLs similarly.
Pick a component on the site which is loaded last and use Object Cloning to 'pause' for it to show up. This should give you a decent surmised time Also loading of a website depends on the internet speed.