The 08 Kombat is still rather easy planing and works well also without any special "tricks". Its just when you use a big sail and want to extract the very last bit of early planing that some tricks can be in order. With the bigger sail already weighting down the nose, the kind of pumping you describe might bog it down to much so that you get to much (curved) nose rocker in the water. A better way is then often to find a slight downhill on a small wave and use that to get planing. Personally, I always put my front foot in the strap first (before planing), look for a small wave/chop to go down and then do a few (or even a single) pump at the same time as I balance the board at the front foot. I use the back foot more to stabilize the board from moving with side-side or up-down with the pumping.
This is something that is rather hard to explain, but it comes natural with some training. Maybe you are even doing it already without noticing. Again, at least for me, the trick is using the front foot, which need to be put in the strap early.