Keith Dysart wrote:

I think you are misunderstanding, possibly because I am not expressing
as clearly as could be. I find it difficult to pick a vocabulary that
will not be confusing due to prior associations with the words. But
then words like 'entity' are too fuzzy.

. . .

The problem I had was the use of "energy flow balance" which implied
equal energy flow into and out of any point at any time. Your more
detailed description explicitly includes stored and dissipated energy,
which as we've both said, makes it possible for energy flow into and out
of a point to be unequal at times, while obeying conservation of energy
by being equal on the average (when dissipated energy is accounted for
as removed from the system). The more detailed detailed description
should help alleviate misunderstandings some readers might have had.

. . .

From Wikipedia, I have just learned that the concept I am attempting
to describe is known as a "Continuity equation".

I can't recall ever having come across that term, but then I'm not a
physicist.

Roy Lewallen, W7EL