The main question is HOW do we realisticly give caps a 'flak cloud' type effect.
Here is what I propose.
1st, double the explosion radius of the flak cannon, currently it appears to be rather small.
2nd, turn the projectile into a mine of sorts, with proximity sensors. It shouldnt have to score a hit, thats the point of flak, but rather just have to simply get close enough to trigger, at which point the target will be at least partly within the blast radius.
3rd, give it a maximum range, say 1k - 1.5k. At that distance, the rounds explode.
If a ship (or station) has flak turrets, then it could potently keep a wall of flak up in a certain direction, which then would force attacking fighters to treat it with a tad more respect rather than just getting in, SNACing it, getting out til recharged.