change the tank fov so that it has an interior like the helicopter. For better immersion and balance (make it tanky but limit visibility). It also helps a lot against motion sickness, new players will use the joystick to move and see the world around them move, but the body doesn't feel movement thus motion sickness or headache. A tank interior will help a lot to remove that sensation of movement as you don't move in the interior. Also works like a blinder many VR games off as option when moving with joystick, which reduces your fov with black bars around the edges. But instead of black bars you have the tank interior. Pavlov VR is a good example for the tank interior in VR. Also the shooting and reloading make it more interactive like Pavlov VR to make it better than the flatscreen alternative Battlefield, instead of the same button presses.