Bigger Diameter 2-Blade vs. 3-Blade

[Sail IC]

Bought a catamaran a couple of months ago, and the fixed props are driving me crazy. Not only the whining noise from them rotating (SD drives, has to be in neutral), but I also get significant vibrations especially when sailing between 6-8 knots changing speed in following seas.

So I plan to change to folding props and more or less decided on flexofold but for my question/thinking its independent of brand.

Folding (and feathering) props are kind of pricy (need two on a cat) and a 3-blade prop is 50% more expensive than an equivalent 2-blade. The benefit of the 3-blade is that it has more bite, gives a higher thrust, mostly from that it has more surface area. Better maneuverability.

Standard prop size and also what flexofold recommend is 17" dia. However, there is plenty of space between the propeller tip and hull (130mm, 5"), so from what I understand it could easily house a bigger diameter propeller.

So if I go with an 18" 2-blade prop, maybe I get the best of both worlds. Better maneuverability than a 17" 2-blade, and maybe not that far from an 17" 3-blade. Then there is the cost saving over a 3-blade

In addition, a 2-blade is more efficient when motoring and lower drag when sailing. Some extra bonus.

The boat is a Fountain Pajot, Orana. 44 foot catamaran, 9.8T displacement, 2x 40 Volvos on saildrives.

What do you think?
Am I on the right track?