I think jitter is a function of the clocks on either end, and not the cable, correct? Regardless, I don't think jitter is an issue in this application, as buffering on either end should more than suffice to get the bits all to their destination in plenty of time.
Yeah, a marginal cable can introduce all kinds of problems. That's true with any kind of cable.
bs
My casual research into this tells me that both synchronous and adaptive USB modes derive the clock from the actual signal on the cable and slopey signal edges on less than ideal cables can cause additional jitter. The adaptive mode is supposedly can be made very jitter resistant but not jitter free. The asynchronous mode is the only mode that can be jitter free as the destination device always runs off its own fixed clock and controls the speed of the transmission by sending feedback to the host to ensure the receiving buffer over/underrun doesn't occur.
Found this puppy: https://www.passmark.com/products/usb3loopback.htm
The price is accessible and looks interesting but it won't report jitter, so not entirely useful for USB audio testing.