Good catch by SteamFrameHub here: snippets of the recently released Steam Frame kernel source code contain references to a possible variant of Valve's new VR headset with upgraded OLED lenses. A failed prototype, ditched during development? Maybe not – one of the related code branches, which codename the device 'Planar,' was updated on October 2nd, weeks after the LCD-lensed Frame opened for reservations.
There's details, too. The OLED lenses seem to have a native resolution of 3,552x3,840 and a max refresh rate of 90Hz, suspiciously identical to the MicroOLED lenses used by Samsung's Galaxy VR headset. In standalone VR play, this would be much harsher on the (allegedly unchanged) Snapdragon SoC than the current Frame's 2,160x2160 eyescreens, but then the code also hints that Valve are getting around this with a cousin of the Frame's foveated rendering and foveated streaming tech: foveated scaling, where higher pixel density is used where your eyes look, and lower, less demanding pixel density is applied where they don't. Interesting! Even if right now, the whole idea of a Steam Frame OLED doesn't make much sense.