You made it! This video is a great step-by-step lesson of how to set up those HID features and functionally (Call Accept, Call Decline, On-hook, Mute) that Kevin detailed in his blog. Plus learn best practices on how to integrate that onto your touch screen controller.
And we even have a Q-SYS Design file for you, just to get you started! Download it here: https://bit.ly/hidqsysfile