Good progress. If you feel rushed during the maneuver try being lower on the approach, then do a quick full throttle punch out to toss you over the obstacle with your throttle at minimum. This will use the inertia of the quad to give you maximum air time so you can smoothly setup for the path underneath.
Nice training session. I would suggest to train it higher up in the air doing a bigger split-s and slowly try to make it tighter around obstacles later on.. including the tip from @mattpostak