There's also something else to consider:
FreeSpace is a control-heavy game, so unless you can use a joystick/gamepad and a keyboard with the Quest standalone, I don't think a Quest version of FSO would be feasable.
You can use Bluetooth keyboards and controllers.
Also, the motion controllers can have similar inputs to a gamepad.
But if you want untethered PC-VR with the Quest, you can either use AirLink or VirtualDesktop.
On the other hand, as FreeSpace and space combat sims in general are a sitting experience, I don't mind the cable much.
(I'm a member of the team behind XWVM and play it a lot in VR.)
I think the native implementation on Quest is more about convenience and the barrier of entry of having a gaming PC than the cable itself.
That said, I agree that implementing VR on PC would be the first logical step.
Personally, if I wanted to implement VR-support within FSO, I would make use of OpenXR in order to support as many headsets as possible if not all.
Indeed, OpenXR is the way to go, both on PC and Quest. If someone manages to implement VR in PC, that part should work the same in standalone (Quest or other Android headsets).
The other building block is to have an Android port that works with OpenGL ES, or ideally Vulkan. I think there is some functional fork already?
I wish I had the skills to actually implement it.
Should any efforts to implement VR ever take traction, I'd be happy to do some testing with my original Oculus Quest.
(By the way: The XWA Upgrade team somehow managed to implement VR support without any source code and it works and looks fantastic.)
I am collaborating with the VR mod for XWA, and indeed not having the source is very challenging, but there are many other mods that manage to do it. You need to understand the rendering part of the engine and modify the right addresses in memory to modify the 3D transformation matrices.
In XWA all the 3D calculations are done in software (CPU) and the drawing uses a legacy API (DirectDraw). In fact blue_max and others in the community managed to do a 2D->3D reconstruction in a ddraw.dll wrapper. Once you can capture the draw calls and have the 3D primitives, it's a matter of applying 2 separate view-projection matrices and render to each of the eyes. But that's just the easy part, then you need to fix things that break because they were not designed/implemented for stereo view.
I have been working on an OpenXR implementation for XWA but lately I focused on solving other issues in the SteamVR implementation.
I have good very good memories of playing Freespace 2 so maybe one day I will give it a go.
Maybe doing it with source code will even seem easy in comparison 😁