If I understand it correctly most parameters can be negotiated by the usb controller of a device. It should be possible to plug it into a device and see the specs of the cable and the charger somehow.
Yeah. A lot of IT people would pay for a box that you plug a USB cable into and it tells you what the cable can and can't do. Simply reading out the specs, not actually testing whether it can perform to spec. (Although a simple test of the latter should be possible. Baby computer, it sends data at all supposedly supported speeds and sees if it gets the results. That would catch the ones that couldn't but could miss a flaky one.)