I have gained decent ownership of the Bb below double high C, hit the double high C with decent accuracy (I admit I yet own it), but today, while getting more self-assurance relaxed totally in going for the A just below the Bb, over shot it (from being so relaxed) and hit a double high G. Wow! It projected! Scared the crap out of me! Do I own it... heck no. But lip massage, rotating mouthpieces and relaxation has done more for me in the past 2 months than all the 40 years leading up to this time.
I am not doing this to play higher, but rather to have more endurance as the EBQ has been playing more and more, and our book of originals are killers. The "side effect" is range building I could have only dreamed of achieving just a few months ago.