Well on the contrary
I removed my Kiwi Prop on my last yacht, a lightish Ross 35, (having previously taken the Kiwi prop to the manufacturer for refurbishment (I live in Auckland)). These are not well regarded props here and are often referred to as an underwater fan.
I changed to a 2 bladed Flexofold. Improved immediately on the race track, gained a full knot under power at cruising revs and near 1.5knots flat out and was more efficient in reverse (the engine did not want to stall and significantly reduced walking) which surprised me more. Not all folding props are the same, some are bloody hopeless.
When I re-propped my current Dufour 45p from its Volvo 3 bladed folding, to a 3 blade Flexofold, the difference under power was even more pronounce!
I am now a fully certified Flexofold fan.
The membership association for owners of Dufour Yachts