I have the same issue with a brand new DW 5000 turbo. The noise is only when the chain is returning to the sprocket on the rebound. Putting a piece of paper towel under the chain where it meets the sprocket solves it but not exactly ideal. I checked the alignment of the chain by adjusting where it meets the footboard & when visually lined up straight, it still makes the noise. I briefly had the accelerator version of this pedal for a day and don't remember any such noise, but the sprocket on that one is smaller.
I see the thread is months old. OP, what did you end up doing?