Notice that this method provides an in-between bid in each case. This comes in very handy. Opener now has an option during the minor suit transfer. He can either bid the minor suit responder has shown, or he can make the in-between bid which is encouraging. To encourage, opener should have 3 to a high honor or 4 small.
Responder can now make an intelligent decision for a change.
He will bid 3NT if he had an invitational hand, rebid in the minor suit with a bust, or get excited with a slam going hand. He will always have six or more trump . The only type of hand where it is unnecessary to transfer holding a long minor suit is a hand that definitely wants to play in 3NT, no more, no less. Yes, you can cover more hand types then if you were just using 1NT- 3 Minor. Also you can transfer and then ask for aces and use Roman Keycard Blackwood.