It appears the
AIr 2 has a set up that is similar to the Mini's. See the bottom of page 38 / top of page 39 of the v2 of the
Air 2 manual.
Assuming the set up IS THE SAME and that the response mode to the CSC position is “Emergency Only” (probably the default mode) then the CSC stick position will almost certainly NOT STOP the motors whilst the drone is in normal flight, irrespective of how long the CSC position is held.
I have experimented with this with the Mini, and sent the Mini up to 100+m and put the sticks into the CSC position and held them there. The drone descended in a more or less helix IN CONTROLLED FLIGHT and even slowed its descent as the ground came within range of the VPS system. I let go of the sticks when the mini was under 1m from the ground and it hovered perfectly normally.
HOWEVER if the response mode to the CSC position is “Anytime" the motors will stop after the CSC position has been held for approximately 2 seconds, again I tried this with the mini in the 'slow flight mode' (so that the height required was minimal) the Mini ended up freefalling under 50cm onto grass.