Pfthb

I need:
Print a large number of PDFs with duplex on specific output printer feeder

I have:
printing using ghostscript with 'mswinpr2' device

using (GhostscriptProcessor processor = new GhostscriptProcessor(new GhostscriptVersionInfo("gsdll32.dll")))

 List<string> switches = new List<string>();
 switches.Add("-dPrinted");
 switches.Add("-dBATCH");
 switches.Add("-dNOPAUSE");
 switches.Add("-dNumCopies=1");
 switches.Add("-dPDFFitPage");
 switches.Add("-dFIXEDMEDIA");
 switches.Add("-dNoCancel");
 switches.Add("-sFONTPATH = C:\Windows\Fonts");
 switches.Add("-sDEVICE=mswinpr2");
 switches.Add($"-sOutputFile=%printer%settings.PrinterName");
 switches.Add("D:\11.pdf");
 processor.StartProcessing(switches.ToArray(), null);

Problem:
one job in the print queue consisting of 2 pages takes more than 50mb, while I have more than 1500 PDFs with 1 000 000 pages

What i think to do:
Convert PDF to PCL or PS, edit these files and somehow pass the settings (duplex and specific feeder). Then send edited PCL or PS file as RAW data to printer

Question:
How can i pass the settings to PCL or PS?

Since PDF files can't contain device-specific information, you clearly don't need to pick such information from the input, which makes life simpler.

Ghostscript's ps2write device is capable of inserting document wide or page specific PostScript into its output. So you can 'pass the settings' using that.

For PCL you (probably) need to write some device-specific PJL and insert that into the PCL output. However, PCL is nowhere near as uniform as PostScritp, it'll be up to you to find out what need too be prefixed to the file.

[EDIT]

You don't use -sPSDocOptions, PSDocOptions is a distiller param, so you need:

gswin64c.exe -q -dSAFER -dNOPAUSE -dBATCH -sDEVICE=ps2write -sOutputFile=D:out.ps -c "<</PSDocOptions (<</Duplex true /NumCopies 10>> setpagedevice)>> setdistillerparams" -f D:.pdf

Notice that you don't need -f (as you have in your command line) unless you have first set -c. The -f switch is used as a terminator for the -c.