How good are you at hiding behind islands? Propulsion Modification 2 (4th slot) and Concealment Modification 1 (5th slot) can help with this, with the former allowing you to back away more quickly if you get spotted and the latter helps keep you hidden.

Otherwise, Main Battery Modification 3 (6th slot) should be considered optimal to increase her rate of fire. Do you want to go for range or DPM? For range, take Gun Fire Control System Modification 2 (6th slot) and look towards taking Aiming System Modification 1 (3rd slot) to help tighten up dispersion at these distances.

Now you need to choose how to emphasize your main battery. AA Guns Modification 2 (3rd slot) arguably provides the most benefit for what's sacrificed to take it. If you don't want to go quite so heavy handed, pick and choose among these for a softer AA build. Are you going to play an AA ship? If you are, then take the special upgrade, Defensive Fire Modification 1 (2nd slot), AA Guns Modification 2 (3rd slot) and AA Guns Modification 3 (6th slot) to maximize your AA power.

World or warships wiki