The 3BB TV Box is made by Innopia Technologies Inc. and ships with Android 10 and a custom launcher. As I operate all other boxes on Android 9 and do not plan to change that I did not attempt to get the 3BB Box functionality enabled on other boxes I own. There is a pretty good video demonstrating the Box's capabilities.

1. To use Harmony as bluetooth remote we need to pair the Harmony Remote with the 3BB Box, as the 3BB Box can only be controlled via Bluetooth:
   1. Install the Harmony app to your phone or tablet from the app store
   2. Connect the app to your Harmony Hub and add “NVIDIA Shield” as a new device.
   3. Put the 3BB Box into pairing mode.
   4. Create a new activity for the Harmony Remote, at the end of which the remote should get paired with the 3BB Box. The Harmony Remote shows up as “keyboard” on the 3BB Box.
   5. If the pairing does not work, or if you need to re-pair (after changing the remote or after a reset of the box), then you need to delete the “NVIDIA Shield” device and all related activities from your Harmony Remote settings. After that, power cycle the remote and the box, then start over from a.
2. The Shield remote has numerical keys (and other keys which, for example, the Xiaomi Mi Box S does not have) which are understood by the 3BB Box.
3. I did not find a way to power on the 3BB Box through the Harmony Remote, so I decided to just keep the 3BB Box on all the time, and set this accordingly in the Harmony Remote settings. To avoid the box from taking internet bandwidth when not on I manually change the menu to settings before changing to another source or switching off my receiver and TV.