Does the Rift S send its camera feeds to the PC for controller tracking or does it do it onboard and send the tracked controller locations?

Perhaps the onboard hardware is capable of controller tracking as sold, but not powerful enough to enable Quest-style hand tracking. What if in addition to that, the camera data for one reason or another can't be piped over USB to the computer, either because it's missing the hardware that would do the encoding, or because there isn't enough bandwidth on the cable?

As I recall, the original Rift's outside-in tracking was extremely picky about having separate USB 3 ports for each of its tracking cameras, to the point where if you had a three-camera setup it didn't even want them on ports handled by the same USB controller on the motherboard.

Now we're saying "The Rift-S has five cameras and it's connected to the computer, surely it can just let the computer process that data." I doubt it's that easy.