Unfortunately I have not found a way to null or input an object into the JSON. The config validates JSON on submit, and since the input is missing the catalog won’t render correctly.
Sometimes we’re able to have the objects already within the config and have an invalid value that would result in it not being created. Then if you say ‘yes’ to a loadbalancer you input the correct value.
Check out this example @rboyd created about disk adds. Uses the same concept: