That answer needs clarification. Do you mean create a single float parameter and name it “Blend Radius” to gain access to the blend weight value as your camera moves into and out of the volume.
I tried that and it doesn’t work. My custom postprocessing materials are acting binary at the moment. They turn on 100% the moment I enter the edge of the blend radius on my volume. I’m searching for a way to smooth it out. I even went digging through the source code. In the source code it appears to be trying to take every parameter and scale it down to 0 via the blend weight.
Any further advice on this topic would be wonderful.