No hot spots and perfect blending
I delete the hard angles where you don't want it.
Parts are lightly filed until you can barely feel the transitions with a fingernail. Then they are sanded up to the required grits for finishing or polishing.
The goal is for there to be zero perception of where parts end and begin when the gun is in your hand. I aim for zero discomfort so that you can shoot the gun as long as your grip can handle it.