Attack Speed Reference

I noticed random increases of 30ms while holding down the attack button. There seems to be no specific trigger. It happens with all skills listed (with the only exception of Hurricane thus far) and across all weapon speeds.

this means that holding your skill button speeds up your attacks by 30ms right? So that means aran have a dissadvantage here? Does the 30ms increase also work for faster2 capped attacks or not?

Or am i reading you wrong and does the 30ms increase only have to do with your meassuring?