Only changing relative positions to each other or other combatants require a fly/drive manauver
GtA locks in your targets arc to shoot at, which means you are in that quadrant in relation to that ship. It means you can fire on that arc and deny your opponents ability to turn away in time to present you a different arc.
I am not so sure if it locks your nose at the same time to his shots. You might be still able to pull away in time and choose a different arc for this shots to hit.
Keep in mind a round is a lot of time and there is a lot of movement happening even without Fly/Drive, gaining shots, evading fire, starting attack runs against capitals and turning away afterwards. (here the attacking fighter can pick his attack vector without GtA). I would assume that GtA allows to do the same against other fighters and if those fighters don't have a blind shot on the chosen arc, you can still choose your own arc, though I don't have the exact quote from the devs in mind, but I am very positive still that your nose is not locked in, just just stay on the enemies tail, but not necessary sniffing it all the time.
It would be rather unrealisic too, as you need to think and plan ahead your course to stay in control and keep your advantage, having that kind of advantage is more than just staying behind your target, but managing your own flight vector, distance and speed in a way that your target can not successful break out, which usually allows you to do control which sides you present to your target. Only exception to this would be your aft section, which is kind of hard to use against turret ships while maintaining a position behind … unless your target ship is flying significant slower (i.E speed zero) than you and for that see the rules when firing on sil 5+ ships.
So I guess for convenience reasons I would require GtA to lock in arcs which face each other. Does not need to be the nose, in a turret ship it might be more convenient to keep do strafing run and present the opponent port or starboard, but at least in a star wars setting I would rule out a aft-aft config for GtA. What you btw certainly can do is fly ahead of an opponent ship and present your aft to their fore or keep going to one of their sides with your aft (in which case you are in the fore-port or fore-starboard sector of their arc. As GM I would actually give setback dice for that GtA option, but still allow it. ^-^
Hope this makes sense and does not overcomplicate things for you. And now please excuse me, I need to get my hotas out and go for a round of TIE-Fighter to bring order to the galaxy.
(Shame we have no shield hp to actually do shield energy management and switch up sides with additional GtA actions to deplete several shield arcs and increase your shield buffer that way … I guess they need to stop somewhere before the whole game becomes an awkward space combat sim tabletop. °_^ )