Nice idea.
I have just implemented it in GpsarPro 5.23, you will find it in "Speed"-->"Jibes Analysis". At the bottom of the window, there are two new lines : "jibe master 1/2 hour", and "jibe master 1 hour"
When you click on one of these results, the time selection is done over the corresponding period, and so are the different graphs and the 2D view. The time is also positioned at the start of the section, so that if you click on "play" button, you will watch the corresponding action.
Note that the computation first relies on the GpsarPro rules of what a jibe is, according to the computed wind direction (if necessary, you can adjust it through the weathervane and then recompute, but it usually does the work correctly by itself with windsurfing tracks), and according to a minimal entry speed (settable in the interface, 10 knots by default, otherwise it is not considered as a jibe). And of course, a tack is not considered as a jibe...
The screenshot below is from data of one of you... who will certainly recognize himself...
I have not thoroughly tested this new feature. If you play with it and manually find a better score than the software does, please tell me!
Yann