Panasonic only recently added support to control their cameras over USB and released an SDK for that at the end of 2020.
While we don’t actually use the SDK, we do use the same PTP protocol, and therefore can only support the same cameras supported by the SDK.

On top of that there is another limiting factor: Socket types and layout. The Unleashed plugs into the USB port, and its cable into the HDMI port. We made it really, really tiny, but none of the Unleashed models can fit if these two sockets are too close to each other, or to another protruding physical feature on the camera. That’s why we don’t officially support some cameras even though they might be perfectly usable with some adapter cables.

The BSH1 and BGH1 are not compatible because their USB-C ports are too recessed and too close to a wall.