isolate/lock keyframes

I'd like to use proportional editing in the graph editor, but limit it's affects to specific keyframes only. At the moment this isn't possible (you cant get the shape of a large falloff to affect a small area of vertices).

My suggestion is to use the same workflow as mesh editing in the 3d viewport. Use shift H to hide selected keyframes, and alt H to unhide. When keyframes are hidden, they would not be affected by operations such as proportional edit.