I've been using the same poles with grip ledges similar to black Scott poles for over 29 years and no wrist problems. Originally, I was taught the pole plant (yes I mean plant) occurs at the near the ski tip angled from outside in (to avoid running ones self through). I am sure a few of the older skiers know exactly what I'm talking about.
Now a days (last 40 years or so) in most cases, a all I use is a simple flick of the wrist to touch the pole nowhere near as far forward if forward at all as previously taught as a youth. The only time I reach anywhere near forward and plant a pole is in steep and deep bumps or ugly terrain for the first turn or two too get me started the right way (old habits die hard) beyond that flick of the wrist will do. That pole as a pivot/stabilization point is a wonderful thing (mind you this only works if you ski with longer poles). Downside to this done wrong it hurts.
The shelf on the grips is great for pushing in flats.
One complaint I have is that I see a lot of improper pole planting, which can result in injury(both wrist and body) on the slopes. I think the run of the mill instructors (present company are definitely not run of the mill and do bring skiing to the next level) don't fully teach or emphasize good pole technique.