Printing in reverse order has no effect in KDE print dialog (printed from okular) - printed in normal order.
there's no such thing as KDE print dialog, and print manager only manages printer's an it's jobs, please report this but to Qt upstream.
Print dialog in okular related to Qt, not KDE?!
Yes, it's a Qt dialog and this component is not related to Okular, as I said this manages printers not what you send to them.