Their risk tolerance would probably be greater if both towers were fully operational. But any damage to the only functional tower during booster catch = an automatic abort to the ship catch one day later, and the ship catch is what was really interesting at this point of development.

The previz imagery of their plans for the Louisiana coast showed pairs of towers dotting the coast. At first I thought they were for alternating the cadence of launches, but now I wonder if one is to catch the booster and the other to catch ship.