RE: .46AX behavior without baffle
I'd suggest trying a 10x7 and you should gain a little more speed.
We race those engines locally on quickie airframes and hit 125 mph. As you mentioned it doesn't seem possible based on pitch and rpm, but its been well substantiated.
They are nice motors, with the 10x7 you should be able to peak in the low 14's, back it off about 400 rpm and fly.