You will need to carry some throttle throughout maneuvers as the Extra is not really designed to be a "glider". Yes, there is high wingloading, but that does not mean it will float. All my 3D stuff seems to drop quickly when there is no power. I believe the huge props proportionally to the plane may be a factor to that because there is drag caused by the slowing prop. I never fully shut off the motor during any flight. You will need to use your throttle and fly through the maneuvers.

The ESC is programmable, but you do want it to be off or no brake. With the ESC braking fully or some you will notice a consider amount of torque taking effect as the motor has to start up again. To fly smoothly and with some precision you would want that brake to be off.

Any easy way that I found to learn how to adjust with the correct aileron and rudder inputs during a harrier is to get some altitude and do an "elevator" m,aneuver. With full up/down applied and the motor rotating slowly, the plane drops almost straight down and you will quickly learn how the plane reacts to your aileron inputs and and how to use the rudder to control the plane as it glides down in a controlled way.

I hope this helps. Have a great day!