Allow Enabling/Disabling Portions of a JSON Body

I have a JSON API that can accept multiple, optional parameters. Right now, I must add or delete the parameters from the JSON body in order to change what to send. It would be great if there was a way to turn on/off sections of the JSON body similar to how there is a checkbox that can turn on/off Params and Headers. This would allow me to write a full-featured JSON body, but allow other users to turn off parts of the JSON body when they don’t want to send the optional arguments.