More info would be good. Am i right in understanding that you used to have 2 shrouds, went to one and are now thinking of going back to 2? Sounds prudent. Shrouds aren't just there to hold the mast
up, they also control it's stiffness and shape. If it was designed with two it probably needs at least 2. Only drawback I can think of is weight aloft, which reduces angle of vanishing stability and alters the movement of the boat by making it less sharp / increasing roll time.