Here's a formation flight video clip of an inexpensive Head Tracking system driving a panning DJI goggles v2, Caddix Nebula, mounted on a very fast Durafly EFXtra:
Here's a photo of the airplane and the larger camera pod. This pod has room for flight controller, GPS.
Here's some closeups of the pod and camera assembly (note the 4.5g servo used here)
And here's a photo of the head tracker which slides nicely into the 'standard' analog mount on DJI headset:
All the plastic parts are 3d printed and I continue to iterate on the design (Nebula Nano camera, gear types, size, weight):
I'll iterate a little more and then upload the designs to GitHub, ThingVerse along with setup, assembly instructions.