If I designed this RIFT S, I'd have used a 6" riser overhead to a 360 IR Camera which provides it's own light in the same way CCTV cams have. It's as cheap and would be 1 camera rather than 5! For severe tracking positions I'd implement Predictive Tracking based on previous known behaviour of direction & speed and feasible position of direction due to being attached to a limb!
I am a designer but not a coder. I'm just bloody good at pointing out the utter obvious!