TFlexCelPdfExport to make file readonly

Can you please extend TFlexCelPdfExport to make the result read only.
Then it should not be possible to modify the created pdf in any way afterwards (e. g. with Adobe writer).
Just setting the readonly-flag to the file on disk is not enough.

(We are using not Flexcel DLL but Flexcel for VCL, but couldn't find that in the list on your site.)