Permanently Delete Data Columns from Forms Exports?

Hello!

We have completed data collection, and during data collection we needed to collect beneficiary names and phone numbers, but we no longer have use of these and would like to delete them. We have been doing a custom form export and unchecking those boxes, but is there a way to permanently delete only those columns so that there's no chance of them being accidentally exported?

Thanks!

Interested. but, doubt that you can do that.
once a column is created, it's done. to remove that column might mean breaking everything because everything is meta based. taking a column out of there would mean updating so many different objects in the back-end.