Fat sac question x1, 205v, x2, xstar

[kalamalka]

Im about to pull my hard tanks for 750 sacs in my rear lockers in my x1. Before i do i was curious if there was still an overflow option like the hard tanks have? in other words, when the bags are full do they spit the water back out like the hard tanks did, or will i have to watch them so the bag doesnt explode?