But I don't quite get it, why 5 cm rocker on a LW board. It has better low end with less rocker.
You said you have a concave between straps. My first concave was also just between the straps and it sucked, literaly, when you tried to lift the board by handle flat of the water it produced a vacuum beneath the concave. And it took a lot of force to unstick the board from the water. I had to be realy carefull jumping. If I kept the board to flat, it would just rip it off my feet.
I elongated the concave through the tips.
Any problems with your concave?
No problem with the concave it popped out of the water very sweetly.
I am in a wave location. swell, whitewash, waves, chop. lumpy sea even in light wind. A true flat board would just be an horrible in my conditions. I sacrificed some flatness for extra smoothness in the rough. The only flat water I have is in between the white wash. plus I will be riding this board in head to double head wave conditions on occasion. Need some rocker to handle the waves. Again a true flat light wind board would not handle big waves like this.
Also I was expecting a tad more spring back than what I got. So it has a little more than I expected. But in the end it worked very well. It stayed upwind in 10 knots was super smooth through and over the chop and carves real nice.