Hi all. New here, but wanted to answer a repetitive question I see amongst these pages. I am an automotive engineer, responsible for engine calibrations.
These engines stall upon driveline lock due to the lack of engine's ability to compensate at a super fast rate. Basically, when the wheels, axles, driveshafts, and transmission output shaft are suddenly driven hard to zero rotation, this pulls engine rpm down very quickly. So, engine rotating mass (inertia) quickly heads to the negative direction. Because the engine is mechanically controlled, it can not open the throttle quickly enough to compensate this fast decreasing rate of crankshaft rotation speed loss. The engine rpm quickly drops past target idle speed and simply continues all the way to 0rpm. The fuel pump governor commands to add fuel once below target idle speed, but it is too late and unrecoverable, plus it is trying to recover a dying engine with only idle fuel quantity, which is not nearly enough.
The torque converter locking is not the direct cause of this. This can happen in unlocked converter states as well. The act of the torque converter locking does exaggerate this even further though.
In the automotive world, we watch for this condition and we suddenly blip the throttle open to prevent the impending engine stall. This is called an anticipatory compensation, to prevent a situation we know is coming soon. Same with a throttle bump when the A/C compressor turns on, all in an effort to keep the rpm (tach) stable as a rock.
Hope this helps, at least a little anyway.