The poster in #546 thought the correct behavior should be to show all columns, hidden or not. This PR results in the export correctly matching what's displayed, which sounds like a reasonable default, but perhaps to make everyone happy we need to support either option somehow?

I think I misunderstood the poster's meaning. I still think the correct default behavior is to ignore hidden columns.

(1) we already replicate the view’s content when it comes to sorting and filtering
(2) this is what we had in mind when implementing the feature, see #313
(3) w/o an alternative, including hidden columns would leave no alternative means of not including the columns if someone wanted to do the reverse -- they would be left with only the option of deleting the columns and the associated data. Here, the user can simply make the columns visible again to make the view match the desired export.
(4) interestingly default behavior is not uniform - LibreOffice ignores hidden columns by default on png/csv export and Google Spreadsheet does the opposite, can't test Excel

My suggestion is to expand on the export_headers prop like so:

    export_headers: PropType.oneOfType(
        PropTypes.oneOf(['none', 'ids', 'names', 'display']),
        PropTypes.exact({
            headers: PropTypes.oneOf(['none', 'ids', 'names', 'display']),
            columns: Proptypes.oneOf(['all', 'visible'])
        })
    ),

As we did elsewhere, leaving the basic usage simple but presenting a more complex prop for tweaking / advance usage.

This should be simple enough to support, and could be folded in with the fix.

Whether to include all or just visible columns doesn't really fit under the prop export_headers IMO - I'd just make a new prop export_columns: Proptypes.oneOf(['all', 'visible'])

Fair enough. My attempts to minimize props were ill advised.