Re-reading after a session I realize I got it wrong. I was making it in effect permanently (barring enemy pilot taking it away), but it's only in effect to the end of the following round. But another issue came up: assuming the opposing pilot doesn't try to GtA (or fails), does the difficulty reset after it expires? Eg: Krayt Fang (speed 4) vs TIEs (speed 5):
Round 1: KF pilot has initiative, attempts GtA at Hard difficulty, succeeds. TIE pilot just shoots.
Round 2: KF pilot attempts Fire Control, gunners shoot, TIE just shoots, GtA expires
Round 3: KF pilot has initiative, attempts GtA at Hard difficulty...or Daunting? In any case, pilot fails. TIE attempts GtA at ... Easy? Or is it Average because of the previous success in Round 1?
It seems to make the most sense to me that it resets. Because otherwise you'd gain one or two advantages over the course of a dogfight, and that would be it, nobody would ever get another one.
Or maybe that's where an extremely capable pilot can show his stuff, and squeak a couple more rounds out of it...but if that's the case, it seems like a lot of effort to mitigate a single setback die.