Wouldn't it be more like just one cube that changes labels and size depending on the situation? And that would also be related to the amount of energy? The thing that came to mind is Abraham-Hicks "Segment intending" .

"We encourage you to be aware of the natural segments of your day. There are not two of you who experience the same segments, for each of your life experiences are different, but we will give you some examples here:

When you wake up in the morning, the time that you remain in bed after you awake is a segment.... When you get into your automobile, the time that you are in your automobile, moving from one place to another is a segment....

If you will recognize that you have begun a new segment, and at the beginning of each >segment, if you will take a moment to clarify what your dominant intentions are -- what >you most want to receive or give during that segment -- then you will be in deliberate >control of your life experience.
Abraham-Hicks, A New Beginning I, p. 24

Continued...
In the eternal Now there is just one cube the one you are in Now.So those others wouldn't really exist? When your in a car driving,it's not possible (recommended ;-) ) to be in the sleep cube.I can see a parallel with your cubes and what Abraham - Hicks describes if you line up you cubes in a row end to end and consider that you are in that cube Now. The cube you are in Now is the only one that truly exists. The one you left is a memory (exists only in your mind), and the one your approaching lies only in your intentions.
Now as far as the energy expended on each cube so you have stated. The thought that I have been using is that : We have an endless supply of energy ,We are creators. We are made from the stuff that makes up the Universe and there is no end to the supply of energy of the Universe.
It is when we to choose to be limited with our energy supply that we are! sure some things in life do demand a lot energy but there is no end. So as long as you know you are unlimited there are no boundaries!
Thanks for the great question!
peace

Here are a few practical exercises you may find interesting ;

Rub your hands together for about half a minute then with your hands about two feet apart slowly bring them closer together, without touching, feel the energy between your hands, experience the sensation, this energy is the basic building block of the entire physical universe.

The cube is a model of the mind, here is a practical model that you can draw

on a piece of white card with each square measuring 6 cm x 6 cm then fold and glue it so as to form a cube that will look like this, it has 6 faces and 8 vertexes

It is just a cardboard cube however remember that you are working with a symbolic model of your mind and that the reality that you perceive at each moment through your physical senses is in constant communication with your mental and emotional inner world and vice versa. There is always instantaneous feedback, a kind of intimate complicity between the visible and the invisible and the more you focus the deeper the exchange.
Hold the cube in your hand and turn it around with your fingers, each face is marked with a central dot and a specific word ;

order - chaos - male - female - concrete - abstract

that form the three balanced opposites,

Order/Chaos - Male/Female - Concrete/Abstract

Each word represents an abstract energy that can mean many different things that link together in your memory, for example « chaos » can mean disarray, anarchy, clutter, muddle, turmoil, free-for-all ... etc. these words link together in all directions and give a much clearer picture of what the energy « chaos » signifies.

Each of the energies « order » - « chaos » - « male » - « female » - « concrete » - « abstract » describe something that is elusive and vague yet remains an essential force, a fundamental and vital concept that you can feel.

Place your index finger on the male dot and your other index finger on the female dot and you will feel a rush of energy, it is the energy of duality that flows into your consciousness, place your index fingers on the abstract/concrete dots and feel another rush of energy, then do the same exercise with order/chaos.

As soon as you have perceived an energy it is much easier to perceive it again. The perception of energy then moves from your unconscious control to your conscious control and It becomes part of your consciousness , you become aware of it's presence and you start to see the energies at work in everyday situations, with people, places and things that reveal the male female energy balance.

Nature is overflowing with examples of male/female energies ; in flowering plants the stamen is the part of the plant that produces pollen grains, it consists of a flament and two lobes each containing a sac in which pollen is produced and can be considered as the manifestation of male energy - the carpel has a sticky part that collects pollen which then travels along a hollow tube to the part that houses the ovule or egg and can be considered as the manifestation of female energy.

Practice similar exercises with the abstract/concrete and order/chaos faces.

It is now easy to imagine and feel that the cube is internalized and acts as a dwelling place for your mind, that your awareness is in the center of the cube and you can feel the cube rotating and searching for a balance point in your head, with male energy leading straight on ahead and female energy automatically lining up behind you.

Order energy links with the upper part of the left brain and abstract energy links with the upper part of the right brain. Concrete energy links with the lower part of the left brain and chaos energy links with the lower part of the right brain. You may feel a definite click as you consciously link all the 6 key parts together.

Place the cube as in this picture

Place your consciousness in the center of the cube and you will have all the 6 energies operating around you orientated with the male straight ahead, the female behind you and the other 4 energies correctly situated right and left, as you move your head the energies move with you in their fixed positions.

Once you feel comfortable with the cube energies and are satisfied that you have fully integrated and understood their meanings , you can move onto the next shape, the tetrahedron ... have fun

thanks for such a great question

What if I told you to put together a triangle with a square and with a circle and the drawing needs to be equal for all 3 component and the starting point of the shape needs to be at the middle to give a balance for all the shape?

Then would you need to compare your drawing with someone else? If you have 3 kind of people in this world: triangle, square and circle; why would they not understand them self and create inequity? Is it a matter of perspective? Or a lack of understanding? The triangle and the square will become a double triangular pyramid and the circle will become a sphere and they all can balance them self on the middle point. Can you see how those shape relate together? Is it in the light that you can see it? or is it still in the dark and you cannot see it? Know this even complicated stuff is made of very simple things. Is there a problem if one use a stick and sand to draw? Or if one use Pen and paper? Or if one use computer and a screen? Let there be among you a person of understanding.

http://www.youtube.com/watch?v=XJqTufzNoQA

Let there be light, be the light that you can be, experience and enjoy.

I thought of something similar years ago. It is in my journals someplace.

There is something that each person lives in their own way, each with their own happiness and problems.

So this means that whether you are wealthy or poor you still have the same but in a different way.

Wow I wish I could remember what I wrote, it is so close but lost and what you wrote hit on a memory.

It was something like status does not eliminate problems it just changes them. Similar to the saying that, "The grass is greener from the other side of the fence." it may be greener but that is because it is taken care of much more. The people with the greener grass have to worry about their grass, feeding it, watering, it, trimming it, constantly caring for it. So to have your grass as green you have to take on the problems of having greener grass. It is not better it is just other problems, so while the neighbors might not have your problems, you don't have theirs either.

It is just as you pointed out each living in their own cube or bubble. So the poor man has to get up and go to work, the rich man has to get up and track his stocks. If the poor man slacks he could lose a day of pay. If the rich man slacks, he could lose everything he has! So both have problems just each in their own cube of what the world is to them.