I found with the unger alu at 8.5 sections it wanted to come back down to earth once you had passed the critical point..and it did so permanately bending a No4 sections.
I think you will get a "feel" for when you are too high and the pole starts to get a mind of its own. It wasnt so important with the alu as the sections were cheap but perhaps not so with the carbontec. Why not ask Unger direct I am pretty sure they will have tested it to destruction.
I would say that if the bend in the pole is getting close to touching the wall then thats the optimum height-just a guess to try and help. Or if the bends start to bend in a different direction all by themselves, you are at critical point. But I havent even had hands on one of them :
Maybe just for testing you could get the help of two others with lines tied near the top to prevent side slip.