Robert M. Gary wrote:
I'm curious how important it really is to punch in 1200 as soon as the
controller instructs squawk 1200 as you approach for landing at an
uncontrolled field.

Aviate, navigate, communicate. Your squawk code comes under
communicate. It shouldn't be a big deal to reset the code to 1200,
but certainly, if you're busy with other tasks, that's pretty low on
the priority list.

Most of the time, when the controller turns you loose, you're about to
drop below radar coverage anyway, so it's a moot point.