The major benefit is the support it gives to the stock right where the blade is cutting.
Diy miter saw zero clearance fence.
How to make the most effective miter saw fence.
That s especially good for smaller or thin pieces.
Here s how to make one.
Join the strips of wood together using some glue and 2 inch brad nails.
The insert is a so called zero clearance but that s not really effective on a miter saw like this other than to limit the amount of sawdust that collects in that slot.
Cut another piece 4 inches wide for the fence itself.
Cut two pieces of stock about the same length as the base or even longer if you want additional support for long pieces of molding.