I don’t know how it could be done technically, but Ideally Nu currencies could be used within Safenet by having a trusted escrow / vending machine which operates on both the Nu blockchain & the Safe network (e.g. B&C exchange + Safex working together).
If 1 NuBit were sent to the escrow on the Nu blockchain (or burned), 1 NuBit would be created on the safe network under the control of the depositor, and vice versa.
NuBits on the Safe network may be a coin that uses a structured data method like described in this thread: Custom digital tokens
It would be great to have the stable store of value aspect of Nu currencies on the Safe network, and as Safe may become used by lots of non-crypto people, it may also significantly increase the market for Nu currencies.