Has anyone managed to put the USB 2.0 header to practical use? Or is the best route just a USB hub?
What do you mean specifically? The USB port can be used directly, cannot it?
This model has a USB3 port, as well as a USB2 header inside[1]. My guess (perhaps wrong!) is that one just has to solder a USB port onto it to gain a second port.
[1]media:gl.inet:gl-b1300:gl-b1300_v1.31_pinout.jpg [OpenWrt Wiki]
Yes. You can solder wires to use USB2.0 port. But unless you have skills and knowldege, just use a hub.