The !VWMDesk 0 seems to work, though not consistantly. But I figured out a potentially better way using !VWMExec with "^@wt^". When !VWMExec !alert "^@wt^" is assigned to a button it gets the title of the active window, not LS (as I expected).

I was hoping to use this in conjunction with a WndMan bang but you can't target a window based on it's title. I know One can, but it doesn't "Shade" or the ability to "toggle" between Max/restore.