Mauser looked into these modifications as the original P08 grips also had the tendency to move around on the frame, especially with age when shrinkage took place.
The initial 'fix' was to install the 2 metal pins in the grip edge, but this meant that the grip edge was quite pronounced and not that comfortable to hold.
The next solution was the small pin through the frame that would spike the grips in place. Worked better, but again, with use, the pointed pin would wear out the hole and develop play.
The best solution is not to use wood as a grip material
