Stereoscopic panel - Undocumented or non-existent?

According to Meta's Design documentation on Panels

Panels are the rectangular surfaces that display 2D (and sometimes stereoscopic) app content in Quest.

Panels can contain stereoscopic app content. However i could find no documentation how to accomplish that and in the examples i checked this feature wasn't used either.

Is the official documentation mistaken about the possibility to display stereoscopic app content?
If not how is that accomplished? A self contained example would be appreciated.