I used the "Microsoft MCE Keyboard" on my Harmony 650. But...in looking at the setup for my DVR setup I am using mostly Flirc IR buttons. (Not sure when I changed that) The Blue button on Flirc is the one that controls the Home function. pressing "Left Win-Key + Enter" on keyboard or via flirc is the "Home" button On custom key combinations I just use "full Keyboard" in the Flirc software and then use the mouse to select the keys I want to program and then press the IR key I want to use.
This was created for a FireTV box originally but I put it into my New Mi box and it seems to work perfectly. This was setup for both Flirc and the Microsoft MCE remote. The MCE remote has more buttons and I can also use it with the XBOX Kinect voice controls. I setup the Harmony for MCE because it just works better. FireTV MCE.fcfg