CP prob using a MA prop or those old Kavan props that would come apart at 8000 rpm. I have ran many 16 APC props around 11,000 in the air not recommended by APC but they did hold. Also a Carbon prop can be had for about 400 dollars for the mold but don't copy any prop made out there with out the owners permission, IE don't be China.
A 16x10 and 15x12 are very close to the same load in not a a few more RPM to the 15x12 over the 16x10.
If you really want to try some rpm with it get it away from people and or try a wood prop also.