Once I had looked into this a bit more, I decided to move away from the
performanceTiming plug-in altogether.There was a number of small quirky
things that informed the decision, but a major factor was that the data
was only being captured on the subsequent Page View call (or the Exit
Link call, if there was one) - this meant that you end up missing one
measurement in almost every visit, and it's worth noting that the missed
measurement is for the load of the page on which the visitor chooses to...