That's why I said that it would be manual. Actually, it could be semi-automatic - a script could generate all relevant transactions, and a human operator could simply confirm them few times a day by signing the transaction with his password protected private key.

> Customers like having funds available to them immediately... among other things.

Either security or convenience. This service was aimed for merchants, which are used to get their funds from payment processors much slower than in a matter of hours.

Also, that's only one of the solutions that I mentioned. Second one, which is convenient and more secure at the same time, is using multisignature wallets.