I've seen plainer boards used. They work ok. But I don't use them trolling for crappie. To keep my cranks from tangling, I use a mix of longer and shorter rods staggered in order from longest to shortest. I also stagger the distance the lure trails behind the boat. Most rod holders are adjustable and the angle of the rod could be adjusted to make the seperation even greater. Also don't troll cranks right next to each other, try a jig in between. Depending on the size jig, it will probably run deeper than your crank bait. If you are going so fast the cranks have that much left to right wiggle/action to them, you may want to slow down or use a crank with a different lip on it.