[cups.general] alignmargins problem

[RW]

I have a Brother HL-2250DN mono laser printer that I'm trying to use
under FreeBSD. I have it working under CUPS with: 

    Generic PCL 6/PCL XL Printer - CUPS+Gutenprint v5.2.7
or  Generic PCL 5e Printer - CUPS+Gutenprint v5.2.7

but I'm having a problem with the margins. I've tried using
alignmargins but only the /Margins[] part works, .HWMargins[]
is ignored.

I read in a previous thread that .HWMargins is only understood by
Ghostscript. Is Gutenprint not using Ghostscript? Is there a solution
to this?