Hello @BarbaraMM 

You read and understood it right! Not at all recommended to leave empty as then the numbers, currency, date formatting etc. without this property will rely on the browser which will certainly bring data inconsistencies between users.

I would recommend to create script to override the default format like currency, date etc. to generate and export such report.

Let’s hope to see a non development and an easy alternative from ServiceNow support (if any such exists).