Keel only on rocker flat maybe, not the front part of board.
rails rounded to " a bit" behind front fins.
Keel may help with chop, but it will very likely limit top speed.
Analogous to variable deadrise in powerboat design I think.
If limited, the "keel" will produce a chop benefit with a limit in top speed that falls outside the board's normal performance envelope (ie >/= 30knots).
Tricky part, these boards are nipping at that limit already, and in powerboats the variable deadrise strategy kicks in at the same level as a maximum with plenty of power. In fact as a rule of thumb for powerboats, variable deadrise is most suited for boats that top out under 25kts.
Just cogitating a bit,,,,
Starboard some years ago made a (slalom oriented??) windsurfer that had something like a keel. Don't think it caught on.
Worth trying though....

I don't think that would solve the problem I had? Having the back part of the board flat or with double concave or keel should not effect how high the nose is when it hits oncoming chop. It looks too counterintuitive and will require a lot of sanding effort to try. I think I'll stick with flat for my current board.

What are people using? some kind of double concave for a bit more control/stability when board 1/2 out of water?