Distiller Parameters - setPagedevice

Good day,

I'm hoping to convert something from a PostScript that doesn't work to a PostScript that works using Ghostscript 9.25.  This command works perfectly:

gswin64 -dQUIET -dBATCH -dNOPAUSE -dDUPLEX -sDEVICE=ps2write -sOutputFile=gmsnewpostscriptdup.ps gmstestfile.ps -c "<</PSDocOptions (<</ManualFeed false>> setpagedevice statusdict begin 0 setpapertray end)>> setdistillerparams" -f

...except for the fact that it doesn't carry over the original PostScript file's simplex/duplex information. Does anyone know the setpagedevice parameters that would allow me to do that? From what I understand, the parameters are Adobe-centric, so the program (Ghostscript) that I'm using for the actual tearing-down/rebuilding isn't important in this case.

Thank you!