Re: Backside board design.
You're getting a little impatient, but let me suggest a couple of things, asymmetric board designs have been around since the year dot but the usual view is they only work going one way and functions such as cut backs and full round houses break down due to the extreme nature of a single facet design.
Another thing would be wide-ish round tails or diamond tail , forget any severe pin shape and are you talking long or shortboard? What are your skill levels?
You could up your volume a little to give flotation but too much and it will be sluggish. My suggestion for any break where you consistently ride se what shape guys of similar ability and weight are riding successfully, that is the shape to go for.
I've taken up troll hunting just for fun, instead of a rifle I'll just use a pun! 冲浪爷爷