I wish the browsers added this, and then allowed users to set their own settings. That aside, has anyone used this and rigged up something to also preload abov

I wish the browsers added this, and then allowed users to set their own settings. That aside, has anyone used this and rigged up something to also preload above the fold images and CSS? Even if it had to be config'ed in a particular way it seems it woukd be worth the effort.