If I were to leave the default behavior as is and add in a new setting called ‘Allow Null’, this would do a few goods for the plugin:
1. Avoid issues with existing radio fields (a developer may have written code expecting the radio field to always contain a value)
2. Provides an opportunity to add in some JS that would allow the user to deselect a radio field option. Therefore ‘Allowing Null’ which makes sense.
3. Obviously allow new posts to load with no radio field selected solving the original issue.
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