You can print in the "monochrome" mode from LR if you are willing to use the standard menu set, not the plug-in. Oh, and I'm can only speak about LM 4.4 on the MAC, I'm running 10.7. I can't tell from you're post if you have tried this path or if it applies.
Under "Print Job" > color management > profile (where the paper Profile usually goes)
select "Managed by Printer"
in Print Settings pull downs
Color Matching, select Vendor matching
Main > Color mode select Monochrome
below the the color mode pull down is a "set.." button, click on it to get your toning and adjustment sliders.
I have skipped the options that I think are self explanatory and don't relate directly monochrome. Hope I haven't forgotten any steps.