It occurred to me that since the Inspire is a closed platform and isn't user-tweak-able like the Phantom, perhaps DJI understood that expansion would be a desireable and added the CAN-BUS port to the I1 controller.
Technically, I think, it's as if the item you plug in is literally on the I1 CAN-BUS, on the aircraft (albeit with greater latency).
I could imagine, for example, a Flytrex addon, perhaps devices that use the FC or IMU realtime data, or provide input to the FC based on device sensor data.
Maybe FPV goggles that plug in to tell the AC the orientation of the pilots head to translate that into AC or camera movements on board. Your camera operator could FPV with head tracking for example.