This is a rather esoteric question. You will get some BS answers. You can get the lowdown from Martin Hepperle's site,
http://www.mh-aerotools.de/airfoils/javaprop.htm , or from Adkins, C.N. and Liebeck, R.H., Design of optimum propellers, AIAA Paper 1983-190, January 1983,
https://www.aiaa.org/IframeTwoColumn.aspx?id=4745 .
Also,
http://www.supercoolprops.com/Maximizing thrust so you can go as fast as possible with a given engine is one thing, but if you are flying stunt, you are probably interested in having the prop thrust change as much as possible when speed changes: adding thrust when the airplane slows down, reducing thrust when the airplane speeds up. The above sources can help with either.
In general, for model airplanes, the fewer blades the better. That allows each blade to have more chord and operate at a higher Reynolds number. In our speed range, a higher Reynolds number is better. There are other considerations: wood makes better two-blade props than three-blade props. Full-scale airplanes have other constraints like landing gear clearance and prop tip Mach number.
For stunt, you want to keep blade diameter down so the airplane can turn better than it would with the optimal (for efficiency) prop diameter. You also want to keep blade diameter down to minimize prop moment of inertia. Reducing prop moment of inertia reduces the airplane's tendency to yaw in corners. This may lead you to more blades. Another reason to favor a three-blade prop over a two-blader for electric stunt is that prop inertia opposing a turn changes less with the three-blader. When a two-blade prop is straight up and down, it has a lot of inertia opposing the airplane's turn; when it's sideways, it has very little. You can hear and feel a shudder from a two-blader in a corner. So can your motor bearings. For this effect, a three-blader is better than a two blader, and even better than a four-blader.