Efficient way to disable Extra field in the Flatsome theme

I use the “Extra” field in the product page to designate newly added items with a NEW bubble. I’ve added several hundred products since we went live with Flatsome. Now I have to go back and remove the NEW designation for most of them.

I’ve tried two different export plugins, but neither of them lists the Extra field as one that will be exported. Same issue with Smart Manager, which provides a good way to update multiple records, but also does not list this field.

Has anyone found an efficient way to go through disable the Extra field in Flatsome? Am I missing something in the export or Smart Manager plugins?