when u load the device, it’ll automatically connect to whichever monome is listed first. if u have two monomes, i’m not sure there’s anything that determines which one that is. i think its random.
i could make it so that when u manually select a different grid, your choice will be saved with your Live Set and it’ll auto-connect the right monome when u reload the set. i could try to get that in the next update. apart from that, not sure there’s much i can do to make it easier.