My initial idea with the beacon is the player starts with it (perhaps an emergency beacon given by the Navy, Marines etc in case of a large scale crisis), The limit could be that it needs time to recharge or you need to find a recharge station. Also to solve the patrol issue, is it possible for them to follow the player?.
The Portable QBR Machine- Hybrids have a chance of dropping a "Quantum Entanglement Sample"- Which is ammo for the Portable QBR Machine- As for the looks of the gun... Can you reskin a custom model, maybe one of these in white with a red cross?