The 12.25X3.75 and a typical .46 will take most .40 size trainers vertical unlimited. On a TT.46 pro... that size prop took my 7.25 lb "TameCat" (discontinued .40 to .60 trainer) vertical unlimited (buzzing the ground to just a dot in the sky) IF I was careful not to lose airspeed in the pull from max speed level flight.

You may run nto ground clearance problems with the 12.25 inch dia prop though... If so, try the 11X5. Yo will see improvement in vertical. But not as much as with the Fun-Fly/3D prop.

Some people will put an 11X6 or 11X7 on a .46.. Yes the 10X6 is a bit on the light side for it. (great for a .40)