This was my concern. How will the custodians not run away with the money? A multi-sig address could be used for cryptocurrencies but you want 1:1 ratio of assets backing up the created nubits, so cryptocurrencies would be too volatile. With the money as the ‘reserve’, I don’t see how it could be audited for transparency and how it could be secured safely without trust (as would be required in a trillion dollar industry).
See my post. I give a slightly different opinion.