maximum depth for bottom contours

Guys, What are your opinions on this, If I put in really deep channels, what are going to be advantages and disadvantages. What do you think the maximum depth should be, for a small wave board.

When you put in channels or add contours to a "flat" bottom, you reduce the effective flat area/ surface that gives lift.  Ive put 2 side channels that are 3cm or a bit > 1 in deep and the board stutters and tracks when the water is pressured on the channels. Strong design brings strong performance but thers a limit and beyond it becomes unrideable.

 Beyond the performance aspect, it will mess with the boards strength and bouyancy.