Tapping still works in the palm detection zones, some palms are detected as tap events. In my case it's actually the top software button areas that I trigger the most, the top right of the touchpad so I tend to randomly click wherever the pointer is when typing.
I think it's fair to disable tapping in the edge regions, even if the regions overlap with software buttons (at least the top ones, don't think we need to worry abou the bottom ones).
Author: Peter Hutterer <firstname.lastname@example.org>
Date: Wed Apr 15 15:21:08 2015 +1000
touchpad: don't allow taps in the top half of the palm exclusion zone.