Several years ago, I developed a Windows USB control interface for an external device that I basically converted from a serial interface to USB. I can't say I remember ever needing to enumerate the entire bus to connect with my device though. That said, your environment or needs may be entirely different from my own. It would probably be helpful to mention if you are coding for Windows or or other platform, as it does make a difference. Looking for a "USB user group" is probably going to get you the hardware people though. If you are having trouble with a specific library, I'd go after the maintainers for details. The Littlewire community on github appears to active (https://github.com/littlewire/Little-Wire[^]) and the libusb people are still very active as well (http://www.libusb.org/[^]) if you're working from the Unix/Linux side.
deep magic n. [poss. from C. S. Lewis's "Narnia" books] An awesomely arcane technique central to a program or system, esp. one neither generally published nor available to hackers at large; one that could only have been composed by a true wizard. Compiler optimization techniques and many aspects of OS design used to be deep magic; many techniques in cryptography, signal processing, graphics, and AI still are.