If you’re doing a low number of pageviews (<5M / month), you can crank your GA SiteSpeed up to 100%, I think. This is a bit of a theory, need to look into it more. I'm going to crank up mine to 100% and see what I can glean from it.
Note this line:
There is a lot you can do with Google Tracking API. Can hardly wait to start playing with this.