Presumably, supporters of moneyfinancing would like the policy to be reversed or slowed down if it looks like it is simply creating inflation, with little or no positive impact on real activity.
For Prof Miles, the only real difference between QE and even more "unconventional" moneyfinancing is that, with QE, the terms on which the money is created "are flexible and sensitive to inflationary pressures" - whereas in the case of a helicopter drop, the terms are more open.