Not needed maybe,but you get much better air circulation when you turn the hides with 2 keys on the back even on split boards,most especially in the head.
I board wolf on split boards and use two 1 inch dowells all the way up from each side of the tail right to the eye holes.Then use a fan to blow air up the back between the skin and the board.

You can see the back keys here,and right up to the eye hole to keep the ears up off the board for air circulation into the turned ear cavity.Drys the back and neck area quickly allowing the all important air circulation up through the hide between the pelt and the board.

In one pic you can see the small fan that does the job.

Once the hide has been turned fur out on coyotes I leave them drying fur out till the hide is dry enough to hold It's shape then I remove it from the board. I then reposition the KEYs so they give me good air circulation through out the length of the hide. Never had a slipper doing It this way.