Nothing wrong with a physical bluetooth controller that can take a smartphone with the interceptor installed. It's not all that different from cellphone rail mounts for actual guns for use as smart optics/augmented scopes with ballistic calculators.
But that also means the ergonomics of the physical controller, including line of sight to the display, and from the camera, matter much more. Again, not all the different from offset mount rail optics for actual guns. Getting a proper cheek weld when aiming long range? Chickenwinging?
If one were really going for it, make basic bluetooth serial modules available for DIY's to purchase and provide controller 3D printing files openly available, so people can build out their own custom setups. Say modules can be configured for use as specific components (trigger+safety, maybe with weapons select)(selector+activator)(rumbler/vibration)(kickback linear actuation vibration). This would make a secondary marketplace/ecosystem platform viable for accessories beyond the interceptor.
If you had this with computer vision tracking with markers/QRcodes (android would be Project Tango capable phones), one could do a basic walking AR setup with a smartphone head mount patterned off current consumer smartphone VR headsets that slot in large smartphones/phablets.