For firing calculations there probably might be a simple solution to reduce the range at which AI is trying to fire. For example a beam has a range of 700. This is visual length of the ship, but for AI this range is 550-600. So it will open fire once the ragter is within these 550-600 regardless of target`s orientation.
That's actually what it already does, except it uses the collision radius rather than the shield radius of the ship. Works pretty well for the vanilla ships - not perfect, of course, but quite serviceable.
But yeah, the engine doesn't support long and narrow (or, I suppose, short and wide) ships very well.
Is that why the AI likes to snipe with beams at max range when they would hit an active shield, but instead just waste flux on empty space when the shields are down?
I've seen this come up a few times (come to think of it, that may have been you the last time I saw it, too
. That's just not true in terms of how the game works (i.e. it's not shooting at the shield boundary), though it may look that way for a certain combination of collision and shield radiuses. I don't
think you'd find that combination in vanilla, though.
More on topic: non-circular shields are most likely not going to happen. I can see a small chance for improving the firing AI to use a better approximation, but it could be the kind of thing that just never gets priority, being both fairly involved and relatively low-impact.