Hi strido,
I'm not sure it would be that simple to add. You make a comparison with "Print Using a Windows Driver", but keep in mind that the postscript output is meant to be printer-independant(unlike Print Using a Windows Driver), and to be able to output on any PostScript printer. So assuming the command for multiple copies is different from printer to printer, we might not be able to keep our PostScript printer-independant, whereas simply sending it as multiple jobs won't cause issues.
Regards,
Raphaël Lalonde Lefebvre