It would be useful to be able to define if a column in a created Excel sheet could be filtered or not.

Usecase:
If you generate reports on regular basis (I.e. daily sales figures, updated through the day) and upload them to a read only Sharepoint (or similar) site, the users are NOT able to use filtering on column (due to the fact that the file is read only). If filtering was defined previously to the upload, then they still would be able to filter. (I have tested: A user with editing rights can add filter. Then the file is possible to filter for the read-only users. So this should be doable.)

Suggestion: Add a true/fals column in the Excel - Create column definition: