Hey there Rufus,
I didn't get to see you fly at the last contest, but I'm not so sure I'd look for the prop to solve your problem. I'll probably get a lot of flack for saying this because I'm constantly told I fly too fast too, but I'll offer my advice anyway ;-)

Fly where you are comfortable. If it is a little quicker than everyone else, fly a little further out to give yourself a little time between maneuvers. Try half throttle too!

Where you are going to notice a difference with a multi-blade prop is on the down lines with low throttle. The multi-blade at full throttle is going to be nearly as quick as your current set up.

Good luck!

Joe W.