That's my understanding. Given that the turbine is used in parallel during takeoff/climb and drives the electric motor as a generator during descent (while pres

That's my understanding. Given that the turbine is used in parallel during takeoff/climb and drives the electric motor as a generator during descent (while presumably still driving the prop) there would need to be a mechanical linkage. Since the linkage is already there, you wouldn't save on weight by using a serial hybrid setup for cruise and the turbine is already sized to be running in an efficient power band for cruise flight.