I am splitting my original question into several questions, at the expense of clarity, because the original question was deleted for being too broad.
I need a large number of USB 2.0 cameras available with low latency on a single host computer. As for why, that’s beyond the scope of this simplified question.
See this discussion: 50 USB webcams in a single computer. Is that really possible?
In short, most, if not all USB 3.0 hubs achieve backwards compatibility with USB 2.0 by implementing a sort of shadow USB 2.0 hub that the USB 2.0 devices use instead of the 3.0 hub. This means that all USB 2.0 devices on a 3.0 network employing these hubs are actually sharing a 2.0 controller, and thus, in reality, you can only operate a single USB 2.0 camera on any given USB host controller, 3.0 or otherwise. (The available bandwidth will always be saturated by the first camera on the network)
I would like to somehow have multiple USB 2.0 cameras on a single USB 3.0 controller.
It occurs to me that it might be possible to perform some kind of USB-over-USB. More specifically, USB-2.0-over-USB-3.0. Rather than just connect USB 2.0 devices to a shadow hub, perhaps the hub itself can act as several USB 2.0 host controllers, and somehow buffer/pipe data to the host computer over the USB 3.0 connection taking advantage of 3.0 bandwidth to allow multiple full-bandwidth 2.0 channels. This would, I presume, require special drivers on the host computer to receive this piped data not as a single USB 3.0 device, but as several USB 2.0 devices. But it strikes me as being possible. Prohibitively complex to achieve, maybe, but certainly possible.
I can’t find any definitive answers on whether or not a device like this exists. My question, here, is simple, and very focused: Does it exist? If so, what is it called / where can I find it?
