Hi Bill,
I don't know the details of the driver for the SC-P8000, but for the SC-P5000, to make a B&W print in ABW mode, one selects Printer Manages Color, then accesses the ABW option from within the printer driver and selects between the various luminance conditions provided therein; Epson recommends using "Dark" for what they call "better results", whatever that means! There is no application-managed profiling. I have no idea whether Eric's approach remains workable and reliable for these newer printers with their different inksets, but if you find a way of operating it and see good outcomes, I'd be most interesting in learning how you did it and what you found.