I suggest to add a InvisiblePoint class to draw invisible points but still being able to click on them. Of course you could set the pen to invisible in the CirclePoint but in my tests the performance improved with InvisiblePoint.
See code in attachments.
Good idea, this might be handy for some people. I'll add to next upload shortly
Cheers mate
added in rev 56, there will be new downloadable zip for 0.9.7.4 in a few minutes