Smarter than CSC is to unlock the fully manual failsafe option available in NAZA mode. The right switch's bottom position goes from triggering a go home to turning off all autopilot functions of the flight controller and it responds similar to how a normal rc heli does. It allows you to make very fast descents and puts no limits on your angle of attack. The trick is that the left stick that controls altitude up/down now is a true throttle and in the centered home position will only command ~50% throttle.
You can switch to manual, perform a quick dip and then switch back to atti or gps mode to help stabilize after the drop. You have to be VERY wary of VRS when doing this and start with some horizontal momentum to avoid losing all lift.Thankfully when you're high up you have more space/time to recover from a near freefall and can pretty quickly get that first 100 feet and then descend the rest in a more controlled manner. Obviously you should practice something like this in a wide open area to get the hang of it.
During one of my practice runs at a beach (with no one around) i came within 20 or 30 feet of the ground before regaining a steady hover, so it does have its risks, but it that has a way bigger survivability factor than simply shutting down the motors and letting gravity take the wheel.
