Very good guys!
I also used a 19x10 laminated woodie on my DLE35R. I used an ESComposites 40G pipe on mine and set the length to 27" from center of head to the reflector inside the pipe, following the curved header. The AEROslaves pipe was for glow engines with the baffle set 3" shorter than the ESComposites gas pipes. That just means that a 3" longer header pipe is needed. The Integral may not have the pipe length necessary.
Point being in the air unloaded, the 9K rpm with the short pipe sounds about right. Let me suggest that you lengthen a couple inches to reduce the jump and the sensitivity. Powerwise it has more than enough for a 12 lb airplane.