The primary thrust vector is on the axis of the engine (which makes sense, generally).
We're already in the realms of a non-Newtonian model in the sense of acceleration vs max velocity.
We have to break scientific reality by limiting max velocity (else, with a big enough run-up and unlimited acceleration, someone could crack open the Earth). So, my caveat here is purely that we do have to apply some unscientific boundaries to what players can do within the AoA MMO in order to keep the universe coherent for everyone (oh and, for the purposes of gameplay, both general and special relativity are also out XD).
However, if we're (non-Newtonianly) saying that the main engine output can only provide a max velocity in a forward vector, then it'd also (from this perspective) follow that there's no way a small-ish lateral thruster on your wing-pod (genre spoiler alert! disregarding why you even have a "wing" in the first place) could provide anything like the same output as the big fat engine on the tail.
Having said all of that, and keeping within bounds of an artificial max velocity, there's no particular reason we couldn't introduce a semi-Newtonian model whereby you could (eg) accelerate a ship up to max velocity using the main engine thruster - and then rotate on an axis to fire back at a pursuer (whilst travelling in the opposite vector to your bullets and maintaining the thrust pre-provided by the main engine), until thrust applied in a different direction. A 3-vector version of Asteroids, perchance?
However, we think that this would only be 'competently playable' by reasonably sophisticated pilots, and that we want the game to be accessible to most everyone without a steep learning curve... so, my current thinking on this is to potentially allow more interesting semi-Newtonian physics in ether specific ship models (with limits), or in specific environments (eg the less "vanilla" areas of space, or a pre-arranged arena combat where either full- or semi- Newtonian physics are specifically allowed and agreed-to by the participants in advance; essentially in an ingame sandbox environment where the suspension of various regular-space physical rules are pre-agreed).
I can't imagine full-Newtonian ever being part of the full-access game (can you imagine!); and I believe that even semi/limited rules will have substantial knock-on ramifications to the generic playerbase.
In essence, we're starting with the one model and the one main vector (but with modifiers to other vectors if the correct modules are fitted); and we're looking at whether a semi-Newtonian can coexist happily with other less-experienced players - outside of pre-arranged arena combats, where so long as all the participants agree to the physics ruleset, then anything goes.
Hope that helps clarify?