Is it possible (or maybe already implemented by someone) to configure the viewport to display stereoscopically at a set frequency dependent on the given screen refresh rate, while having the frequency channeled out as "sound" through the sound card (or maybe over IR or bluetooth) so to sync a stock pair of Liquid Crystal Shutter 3D glasses (LCS) like SegaScope or equivalent stock or "hacked" alternatives ? Hacking example, better hacking, Screen compatibility info pdf
or maybe, since it's a monotone oscillation that's driving a binary outcome (left/right) ON/OFF, and a known frequency (if the max source refresh rate is applied and FPS is stable) it could be calibrated/synced manually without any direct power or initialization from the PC-GPU.
Maybe avoid Quad-buffered (aka CrystalEyes) Quad buffering 2 by NOT presenting the SAME, spatially displaced, image to both eyes, since in this "time-sequential" case, it isn't actually doable. It would make more sense to intermittently display realtime frames from each of the viewports (realtime-sequence).
NVIDIA Fast Sync ...and I'm on AMD, but the process can't differ much