I was able to remap the zap and nav keys using the Activity change button feature, but... it's menu dependent so unless I want to do the tedious remapping for all of the menus in the Watch TV activity, my remapping will only take effect if a certain menu is active (not what I want).

So... I looked at the Advanced section to see about customizing the xml to map the buttons at the device level instead. Wow, is that confusing. Couldn't get any button remap to work.

Has anyone done this?