Plate Your stock ride plate will be basically flush cut with the rear of the ski, by doing the D cut it should get your nose of the ski up quicker.
I used to use one it did the job but didnt last long in the surf cause they are so thin that they tear apart through the middle of the D cut and also get beaten around the pump. best bet is to get an aftermarket ride plate which is thicker and cut it off flush
Yep as the capt says they do end up cracking. The stock one ive got is fine with no cracks just use until it craps out. It hasnt had much use I have got molds for aftermarket ones which can be made out of glass or carbon/kevlar.