More games with the mod. It truly should be either removed or made available for everyone.
One of the biggest unfair benefits is that you can shoot ships that are coming behind islands before the have line of sight on you. This is big since you have your first and accurate volley out before they can see you.
Battleships get the biggest benefit from this, followed by cruisers.
But in all honestly this mod does not break the game, it just needs to be available. Fast cruisers and destroyers can easyly avoid fire from Battleships and in shorter ranges it does not matter if you have the aim mod or not since you are most likely to hit anyways.
The mod changes the gameplay so that you concentrate more on positioning and tactics rather than aiming. I think that ppl are makeing much bigger issue of this than it is. Lead indicators are common in many flight games and even in some shooters. This mod does not make you hit 100% of your shots, at long ranges you are still heavily affected by RNG and as more and more ppl learn to zigzag to avoid incoming fire, the effects are even smaller.