So the project I am working on uses a Teensy 3.6 and I want to add a USB breakout to the loom thats going out of the project box. Since it will always be powered via external can I leave out the 5v port? Just run D+ D- and ground or does it use the 5v as a reference or something? I am trying to avoid the rebooting of the arduino if the usb gets plugged in.