Unity world curve shader graph, how to start curving from a specific distance?

I’ve made simple world curving shader following some online tutorials and cleaning few things up. It’s doing its job, however I have small issue where it curves objects that are very close to a camera. So, I am trying to figure out how to start curving only if objects are certain distance form the camera, lets say 20 units or more?

Below is a sub-graph I use to output a value for a vertex position i.e. curve world shader, this is the one I need to figure out how to modify

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