Jack,
We all know what you say is the professional "buzz" from the CG and
probably what is written in the manuals that you read. But it is not
total reality.

There are many many stories of not being able to raise the CG on
"proper" channels.

I have been told by CG people directly that raising them on some of
those channels is not always doable. They just don't always monitor
for various reasons.

I do agree that CG channels should be tried first in an emergency but
not to rely on them 100%.

Regards
Gary