Wrong approach for making combat "positional".

If the goal is to build combat around flight and positioning instead of reaction aiming that is what being made wrong:

1. Lateral accelerations should be nerfed, not increased. What makes combat "positional" is ability of one ship to take over some "position" relative to other ship. To be able to do that - attacking ship should have more acceleration in direction towards the enemy, while defending ship should not be able to counter that by counter strafing backwards and to the side opposite of attacker. When you increase lateral thrust for all ships - you decrease this ratio between forward acceleration of attacker and lateral acceleration of defender, making it easier for defending ship to turn towards attacker.

2. Rotating speeds. After the attacker ship takes it's position - turning speed of both ships come into play, giving advantage to the ship with more turning speed to able to aim and shoot first. What matters here is difference between turning speed of ships, not absolute numbers of their turning speed. Therefore it's almost doesn't matter how much you change rotational speeds for all ships, it's only matter of difference of turning speed between attacker and defender. Overall turning speed only reflect time that lighter craft can shoot at heavier one, before the heavier one turns towards the lighter. I.e. if difference between turning speed is 10% it may be 3 deg/sec or 30 deg/sec which makes it 30 secs or 3 secs for 90 degree turn.

3. 'Positional' advantage shouldn't be about turning rate to lateral acceleration ratio and that's why: if you make one ship being able to "orbit" other with second ship being unable to face the first - you literally make first ship invincible to the second one, which is very frustrating for second pilot and generally a bad idea. The better idea is plane-like maneuvers, when lighter ship can use it's main engine to gain speed and take good position relative to the heavier one, then with it's better turning rate it can face the enemy faster than heavier ship. Then lateral thrust come into play, lighter ship using it to save it's position, while heavier one tries to increase distance and turn towards the lighter one. With lateral thrust being weaker, than one of main engine of light ship - heavy ship is occasionaly able to overcome lighter ship's initial momentum and face it. That way both pilots can have chance to shoot at each other, while pilot of lighter ship can still use it's advantage in maneuverability. But if you increase lateral acceleration too much compared to the forward acceleration - it makes easier for heavier ship to overcome the momentum gained by forward acceleration of the lighter ship.

So, to summarize said:
 For lighter ship to be able to gain positional advantage and being able to use it against heavier ship, while not making lighter ship invincible for heavier one lateral accelerations should be lowered a lot, like 50% or even more. Rotational speeds should be nerfed a bit, to give lighter ship some time to actually shoot when it achieves it's advantage. Maybe all accelerations and speeds should be lowered so it becomes humanly possible to be able to perform maneuvers and have steady aim in dogfight. That way positional struggle can have some kind of gradient between non-existent and "one ship is invincible to the other".