Aha! A working Optimus Laptop setup for Unity and DK2

I've been struggling with this for a while and finally came up with a super smooth, consistently 75 fps setup with my MSI GS60 Ghost Pro (Intel Graphics with Nvidia GTX 970M). Can't confirm yet if it works with everything, but it definitely works with any Unity build I pump out of 5.1.3f.1 with 'Virtual Reality Enabled'

1) Use Oculus Runtime 0.6.0.1
2) Use Extended Desktop Mode
3) Make sure the 'demo scene' works from the runtime window. Mine wouldn't work until I added a user profile then restarted.
4) Set your Oculus as the primary monitor
5) Hold shift and launch your oculus executable. Tell it to use the display on the LEFT (your laptop monitor).
6) Voila! Now you have a single-camera mirror on your main desktop, and 75 fps running on your Oculus.

Step 5 is the kicker. This is super counter-intuitive, but I realized the main problem I was running into was by setting the oculus executable to run on the RIGHT (the Oculus monitor), it was actually overlapping the mirrored version and the oculus version, basically making whatever I was seeing totally unusable.
I hope this helps a few people out!