IIRC, The internal storage thing is a limitation of the system-on-chip they use. They only have access to a single pci lane, so they decided it's better for the

IIRC, The internal storage thing is a limitation of the system-on-chip they use. They only have access to a single pci lane, so they decided it's better for the form factor and education use-case to connect the lane to a hardwired pair of usb3 ports than a potentially more flexible pci-e port, which would allow nvme storage. FWIW, the new compute module does have built-in access to the pci lane, which gives you the option to use nvme in addition to the onboard flash storage.