Yes, absolutely right.
I will reply you guys about disabled or grey options once I got a new progress.
Sorry for the late answer i was not home lately.
I donāt understand why i need a 2nd monitor exactely and i donāt want to buy another one but i have a workaround for people like me with only one monitor :
Just need to reboot with only the HMD plugged and wait for windows to boot, then plug your monitor, the Pimax will be well detected and the monitor will work as normal.
And yes thanks āsupport-manā, i would be glad to know when these settings will be unlocked ! 
And thanks for providing such a cool device at a really fair price ! If the kickstarter early bird of the 8k is under 600$, i will consider taking one and sell my 4k, otherwise i will just get a NOLO VR kit.
In Direct mode hmd does not function as a normal display.
Your main monitor should be connected via Display Port with an adapter.
DVI & Hdmi can conflict with one another.
Yes you can boot with the PiMax as a solo display however you want direct mode for most apps & such.