This thread reminds me a bit of a discovery a friend made when
building a new home. The attic was to be left unfinished in the
house, but my friend wanted a subpanel installed there for a
future bedroom and media room he planned to build. He got a price
from the electrician to install one with around 12 breaker slots,
as I recall. In addition, he had the plumber rough in a bathroom
and wet bar where would eventually build them in the attic.

When he and I were touring the almost-completed house, I noticed
the subpanel and walked over to look inside. The electrician had
done a great job putting it in, and also populating it with
breakers. The guy had used it to feed branch circuits in several
of the rooms below, eliminating any future expansion the owner had
paid for. I showed this to my friend and there was a subsequent,
"Come to Jesus" meeting with the electrician. The issue was
solved by the electrician dragging more wire from the main panel
and supplying a second load center nearby, but with none of the
slots used.

Nonny

--
On most days,
it's just not worth
the effort of chewing
through the restraints..