A 3-blade Maxprop will almost certainly help you in reverse. Mine does. I've had it for 18 years and tens of thousands of miles of sailing. Made a very BIG difference when I replaced the fixed prop. The blades set themselves to pull as well in reverse as in forward. It did NOT significantly increase drag in forward (no change in boat speed vs. a 2-blade fixed prop; maybe even a bit of a gain).
It did not help in forward; same thrust as fixed prop. But in reverse, it made all the difference. You have to learn to work with the prop walk, but the ability to put on some speed (or brakes) in reverse quickly makes a big difference in boat handling.