Geir Hansen from Norway has been top Tournament Spey competitor many years. He finished 4th in 18ft Spey in 2016 World Championships.
During sweep he keeps hands high and rod becomes more horizontal and the idea there is to lessen the rod tip straightening downward trajectory in the end of the back cast to shoot the D-loop down. That technicue was more evident few years back but not so much anymore.
Rod tip is not lovered during Drift because it already comes almost horizontal in the end of the back cast but what is important the rod tip is not lifted before the forward cast is began!