If the extension is not enough, the chip can be forced to curl faster and pull the wood. Another area that should be looked into is the belts that you are using. Worn or damaged belts can cause the spindle to vibrate. This vibration will show up on the wood as chatter, tear out and chipping. You might also look at the wear on the table and fences.
Worn parts can cause loss of control, creating problems in the finish.
We had limited success with your suggestion, enough that we could start running again. The type of pipe that you are using can reduce the amount of suction that your system will have at the end of the pipe. This can allow the dust to be trapped between the shoe or rollers and the wood surface. I have experienced the same problem. If you are not having a problem on the fence side or the bottom, it sounds like material is not being removed equally from each cutter.