Grids in Profound UI Version 5, Fix Pack 8.0 and earlier could only export data in the CSV file format. After Version 5, Fix Pack 8.0, the property, "xlsx export", was added so that data could be exported in native Excel 2007+ file format.
Customers may want to export all data in the XLSX file format without retroactively changing existing Rich Display Files or customized Genie screens. When the "csv exports xlsx" property is set, then grids whose "csv export" property is true will export data as XLSX files instead of CSV.
If both "xlsx export" and "csv export" are true, then "csv exports xlsx" has no effect.
Where do you save this configuration option? Here.