It's beyond me but this sorta looks like an actual spec for embedding GPS data in a file.
Camera Motion Metadata Spec (https://developers.google.com/streetview/publish/camm-spec)
Yes it is. ExifTool supports that format too. It is used by some drones. Unfortunately none of the dashcams use this format.
If ExifTool were ever to write streaming GPS, this is the format I would use.
- Phil