That’d be impossible. To do that, you’d need the USB ports to alter their behavior on the fly - by making the NAS server the host when attaching USB drives or by making another computer the host when attaching the NAS server to another computer via USB. You cannot have an USB controller be able to change the host on the fly - that behavior is burnt onto the circuitry of the hardware.
But you are right on your other point - the feeble CPU (as well as the small 512 MB memory) is largely to blame for the slow throughput. If you compare EX2 against better performing NASes, you’ll find most of them have Intel Atom CPUs amd some even have Intel i3 CPUs…but those more powerful hardware come at a higher price points. But the EX2 has been benchmarked to have some of the fastest transfer speeds in this class of low-powered NASes. Another factor, believe it or not in the data throughput is the router. See this post of mine → http://community.wd.com/t5/WD-My-Cloud-EX2/Very-fast-transfer-speed-58-6-MB-s/m-p/737810#M531
