Yes Vixen will send E1.31 for the pixlight or other controller to act on.
But you also need to configure your controller so that it knows how to use that data as in which lights/channels are on such ports. I think Keith is hinting that xlights can send that configuration data as well which is something Vixen can't do.
But don't worry, I use Vixen and have a couple of pixlights and have no problem.