This was brought up at TPAC as a way to make inline more useful, to be able to do things that can't just be accomplished with WebXR.

One proposal was to let inline sessions display in untracked stereo, this would give the appearance like a 3D movie. It would not be head tracked or based upon the IPD of the user/device. So shouldn't expose additional risky information to the website but it is functionality that WebGL cannot do on it's own and would be a useful feature.

/agenda to gauge interest and confirm feasibility