According to Apple, the 2017 iPad Pros (12.9 and 10.5 inch) are equipped with a USB-3–capable Lightning connector and Apple already sells a Lightning to USB 3 camera adapter.
However, I am looking for an USB-3–Lightning cable to connect the iPad at full speed to my MacBook Pro.
Does such a cable already exist?
Background: I am using my 12.9 inch 2017 iPadPro as a versatile secondary display connected via Apple's USB-C–Lightning to my Macbook Pro 2017. The MacOS / iPad software stack is Duet Display.
All this works pretty well, however, the secondary display has a nondramatic, but noticeable lag. I assume that the USB-2 connection (max 480 MBit) is the bottleneck here.