chdkptp requires that you use libusb, not winusb.The problem I think I remember having with libusb is that it didn't work properly with the usb hubs. I haven't tried using it for a while so it may have just been something else I was doing but in your experience has libusb caused trouble with usb hubs?
libusb-win32 and winusb are libraries that applications use to talk to the windows drivers. Generally an application is linked to one or the other, and you need to use whichever one the application requires.
libusb works fine with hubs, it wouldn't be working USB library if it didn't. Essentially all of my chdkptp development is done through hubs.