While working on T295074: TemplateData adds empty autovalue we found a very closely related issue. Let's say you have a TemplateData JSON blob with a non-empty autovalue as well as a non-empty default value. Now open the editor and empty both the autovalue and the default. Result: The default is entirely removed from the JSON, but the "autovalue": "" stays behind with an empty string.

This should behave consistent.

Note that a field that was empty before should not be removed to not cause unexpected, dirty diffs.