I can use the keyboard while using the controller. I don't know what you are talking about it being "disabled." I am on a laptop, hook it to the TV so it is in dual monitor mode, and then have to press the function lock key before hitting f8. Not sure what you are talking about.
In fact, I have been using chat on the game with the controller and keyboard since I started playing.
I'll try again. I was streaming from my desktop to laptop when I tried. Maybe it will work when I'm directly on the machine.
For the record... I wasn't second guessing you, just asking because I want to try what you're doing for myself.
And the keyboard is mostly disabled when using the controller. You can still chat but none of the hotkeys work. That's all I was saying.