Ahh that's a little disappointing. I am looking for a printer to use in some software development revolving around a custom CAD/Slicer suite that would explicitly require that usb connection. Don't want to rip apart a 3.5k machine to do so though. The UM2+ looks like it should satisfy that requirement though, am I wrong? I understand it isn't officially supported but nonetheless possible by setting the flavor on the machine to reprap?