I don't know how Schock expects you to stand and reach lever at same time. With that extension could be possible. Mine is even worse as mine is a T with a trigger that must. be engaged to shift between forward and reverse. I leave bumpers permanently on the dock side. If wind is bad coming in or leaving hang some off the boat on your slip mates side for a little extra peace of mind. No answer 4 me but that extension may work 4 u.
On my boat, I could not stand (steering with legs) and reach the engine levers- would still need to bend down and into the blind spot.
I also do the same with fenders, leave them tied to the dock and hang some extras. Have some on the boat on the side that may contact slip mate. So far have not had any issues with contacts, but had some close calls, getting better at docking, although want to be in full control of the boat and not to depend on the fenders. Leaving the dock I take the dock lines and pull to revese out to get some speed up and then jump on the boat and hit the reverse throttle and back out. Works well and in reverse, visability is not a problem as the transome is low.