Mark Hansen wrote:
In this month's AOPA Flight Training magazine, I read an article
which implied there was still some requirement to remain clear of
the ILS critical area even when the tower was closed.

The reason you're supposed to keep clear of the ILS critical area is
because your airplane can affect the glide slope beam. The presence or
absence of somebody in the tower doesn't change the physics of how
microwaves interact with metallic bodies.