Anyone have any good tips for improving the Run Time Estimation in NCPlot?

I can get wildly inaccurate estimations depending on what sort of g-code it is. For example if the file is merely cutting out objects of reasonable size the estimation isn't too far off, but if it is milling something complicated with lots of short moves (such as engraving something.) The actual run time may be 2-3 times what the estimation is.