Thanks. Adjusting the script from this unfinished post, I have
openDesktops = len(system.gui.getDesktopHandles())
monitorData = Navigation.getScreens()
if openDesktops == 0 and len(monitorData) > 1:
for desktopIndex, desktopWidth, desktopHeight, desktopX, desktopY in monitorData[1:]:
handleName = "Desktop %d" %desktopIndex
system.gui.openDesktop(screen=desktopIndex, handle=handleName, width=desktopWidth, height=desktopHeight, x=desktopX, y=desktopY).setAlwaysOnTop(False)
#system.nav.desktop(handleName).swapTo('whatever/window/path')
Desktop 1 still opens on monitor 0 and desktop 2 is now not on any of the monitors.