AFAIK I think there is some difficulty in getting turbines to scale down efficiently with a need of a recouperator to maintain a higher core temperature for bet

AFAIK I think there is some difficulty in getting turbines to scale down efficiently with a need of a recouperator to maintain a higher core temperature for better efficiency. The recouperator is additionally expensive on top of the already expensive turbine cost. Having a rotary with a turbo should be able to work better at a lower scale for a pretty cheap production cost.