Cummings spinner

What has been done for filler panels behind the blades (C/S) for the Cummings spinner? Or just left alone with open gap?

I have one installed, no filler plates as per the manufacture and has been just fine. Been on for 2 or 3 years now. Larry

I added the filler piece.

For a constant speed prop, you have to twist the blades to high pitch to check clearance. The rear edge of my filler plate is almost flush with the spinner backplate.