… and just like that, perfect clipping (using GL_CLIP_DISTANCE0 in the vertex shader, no fragment shader modification needed) & the second render getting the view matrix of the second camera (enabling depth):
Exciting! Now to make sure it works with SteamVR…
EDIT: Ignore the odd flat block in the left view… still working out some bugs in the auto-instancing code… also, eyes have been flipped so I can test cross-eyed for depth 