I filled up that recommended table for you:
Answers (N/A if not applicable)
Provide a detailed description of the issue
Lagging whenever iGPU switches to dGPU or dGPU switches to iGPU.
Unneccessary switching. (read as: ways more then normal)
Does it fail every single time, or only sometimes?
If you follow my steps to reproduce it fails 100% of the time
Brand and Model of the system.
Hybrid or switchable graphics system?
Make and model of any Displays that are used to see the issue (see note2 below).
How much memory [RAM] in the system (see note2 below).
Provide any other hardware needed to replicate the issue.
iGPU on IvyBridgeHardwareLevel
Hardware Stepping (see note1 below).
Operating System version (see note2 below).
Windows 10, due to the nature of this issue this is crucial for reproducing this issue!
VBIOS (video BIOS) version. This can be found in “information page” of CUI (right click on Desktop and select “Graphics Properties”.
Graphics Driver version; for both integrated Intel and 3rd party vendors (see note2 below).
Problem occurs when pairing any intel driver (example: 10.18.10.4276, WDDM 1.3) with any nvidia driver newer then 126.96.36.19912 (better known as 350.12, last WDDM 1.3 driver), e.g. the newest 361.43. (WDDM 2.0)
SW or Apps version used to replicate the issue.
Single display, clone, or extended (see note2 below).
Display resolution & refresh rate setting of each display (see note2 below).
Native res (1080P in my case) and 60 Hz; probably does occur in any other settings as well. Anything below res and 60 Hz would be inacceptable anyways.
AC or DC mode, i.e. is power cable plugged in or not?
Happens in both cases
How to repro
Please provide steps to replicate the issue. These steps are very crucial to finding the root cause and fix.
Important: This only happens when testing WDDM 1.3 with WDDM 2.0 Hardware-Combinations, like Intel HD 4000 and GTX 660m/ 670m, 680m. There is a thread over at nvidia forums regarding the issue as well. https://forums.geforce.com/default/topic/860554/geforce-mobile-gpus/windows-10-and-optimus/1/
WARNING: There are other bugs collected in that thread as well; it´s some kind of chaos.
Hope to hear back soon,