If you look at videos of borderlands 2/Dead Island they are using depth buffer. Im not sure how it compares to Vorpx since all users are using same display and it may allow better optimization.
Shader modifications arent really needed in depth buffer games.
Helix’s games are using NVAPI(Nvidia drivers) and directly interface with 3D vision in normal stereoscopic 3D rendering. I think its impossible to port over.