Hello! I'm upgrading my standard Premiere unit to an XL4 (arrives tomorrow!) and i've also included one MoCA adapter to my order. I'm hoping to use my current premiere unit as the second room... but i'm not sure where I should place the adapter to get the best use out of it. \ If the XL4 has MoCA built in, where does the adapter go in this setup? Do I need to buy a second MoCA box? for the original premiere?