How does the Blast quality of a flak cannon interact with the Blanket Barrage action? It seems like a Blanket Barrage is exactly what a flak cannon is meant for, but as far as I can tell according to the RAW a flak cannon is no better at laying down an anti-starfighter screen than a heavy turbolaser. You do make a Gunnery check, but that's just to determine how if/how much you increase the difficulty of the opposing Piloting check.
And yes, I do recognize that, fired individually, a flak cannon is more useful against a starfighter (or group of starfighters) than a turbolaser. But what's the point of putting a whole battery of them on, say, the Munificent -class (from Lead by Example)?
One thought: since you are actually making a Gunnery check, would it be kosher (or if not legal according to the RAW, at least reasonable) to spend two advantage from the Gunnery check to target a starfighter with the Blast effect? For example, if you succeed at the Gunnery check with 2 Advantage, could you upgrade the check of the starfighters, and target a starfighter with the Blast instead of using it to upgrade the check again?