> Forgive me for saying this but I just do not get it. Why did you need to use > Linux compatibility layer when CUPS is > OpenBSD packages?
According to http://www.openprinting.org/show_printer.cgi?recnum=Brother-HL-5250DN this is not a true PostScript printer. Instead, the Windows and Linux drivers do PostScript emulation. In other words, this printer is not ideal for OpenBSD.