Not sure this is possible. Given that your head is the position of the camera I don’t think the game has anyway to tell where you really are in relation to the plane other than to centre the cockpit when you look forward and press space. Some planes, I am almost in the right position but in most I am too far back and a little low. The world scaling issue probably doesn’t help either.
Thinking about this from a comical point of view, given that it’s VR you could launch the game, be sitting inside your cockpit, but if you’re running wirelessly with your headset, you can literally get up and walk off and go wherever you like. If you then save your camera position standing outside of the plane next to Gate 4 at Heathrow just behind a baggage cart, when you come back in to the same plane but in a different place and load your saved camera, does it put you back behind the baggage cart at Gate 4 in Heathrow? Or am I overthinking this…