With all due respect I would like to also add Vita to the list for this. Just my own personal request. On the PS4 kits you can use a USB storage device for holding the key as referenced here http://www.psdevwiki.com/ps4/Files_on_the_PS4#USB_Mass_Storage
No idea on PS4 but for storing the key on the Vita it's in the SDK docs, I'll check and edit in to this post. EDIT: Code: ux0:data/activate
I have no idea if a USB storage space will actually allow any activation whether a key is present or not, but there is always that chance. Let us know what your findings are!
It won't allow activation. It has an option via usb, but can't find the key. I can't get it to take the key via Neighborhood either.