I have ditched my weights three times. All three were at the surface to assist
with divers having a variety of problems.

Drop your weights you move quicker- shed your gear you move even quicker.

Dropping lead u/w is pretty extreme, last option kind of move....

Even with a total failure of your BCD you would still be able to swim up and
then dump at the surface.

Blue Skies and Calm Seas,