So I fumbled around a while getting issues with multiple keypresses, sometimes needing to press twice on a remote button, mapping, clearing, changing settings etc. Probably blew 4 hours of my life and I think I finally landed on a solution so thought I would share: Harmony Setup: Add Flirc XBMC device (Computer>Media Center PC>Flirc>XBMCGo into "Settings" for the XBMC Device and select "Adjust the Delays (speed settings)"Change "Inter-Key Delay" to 300Create your Activity including the TV and the Flirc XBMC devices.Go into "Settings" for the Activity and select "Troubleshoot"Answer yes then on the next screen select your XBMC device.Select "XBMC responds to some commands either too many times or only occasionally."Change the next setting to "0".Update your remote.Flirc Setup:Clear your configuration.Select File>Advanced and make sure that "Builtin Profiles" is checked (this will be autoprogramed for the Harmony Flirc XBMC device in your remote settings).Make sure "Inter-Key Delay" is set to "0".Close the Flirc software.Plug Flirc into FireTV.That's it. Hopefully this works well for you.
I will be doing some additional steps in the Harmony setup as I noticed that the Menu, Info, Exit buttons are not programmed to do anything and the Flirc XBMC device doesn't have a Guide command. So I will be adding some commands to these buttons (either existing commands or using the Red, Green, Blue, Black buttons to add as custom commands and mapping with the Flirc GUI).
Flirc, if you could add a Guide command to the Harmony device that would be awesome. As noted I will use Green for Guide but would rather have something out of the box rather than configured by me. Also, not sure if there is an opportunity to get these mapped in the Flirc XBMC device and/or get the inter-key delay setting adjusted to match the default in Flirc (if I am doing this right!).