The basis of this question comes from the fact that when one looks at phasal relationships, Pluto (soul) is the end of the line so to speak.
Basically, you have it backwards. The Soul is the BEGINNING of the line, not the end. The way you conceptualize this reveals your inner state - read on.
Every other planet, asteroid, hypothetical point, etc. is measured in terms of phase, in descending geocentric orbit and counterclockwise ie; Pluto to Neptune, Neptune to Uranus, Uranus to Saturn etc.
With one exception. The Sun ( the creative power of the individualized ego manifested from Source). In relation to the Sun, the rule reverses and every planet, asteroid, etc. is now measured in terms of phase from this point of reference
You referred to this in your earlier post also.
The Sun is the base point in calculating phases because of its physical central position in our solar system. That is why and that is all. That does not give the Sun any inherent specialness or uniqueness. You are projecting that yourself onto a simple mathematical calculation.
You may want to give some thought to the nature of Sun/Leo/5th house in your own chart/consciousness, and how you may be projecting a Leonian sense of specialness and importance on things where it really isn't.
Since the methodology is what it is, with the rule And the exception to the rule, metaphysically does the soul enter manifestation through the Sun and get flung out to Pluto where it then begins the long haul back towards source?
Again, backwards. You are projecting your own inner confusion about the relationship between Soul and personality outward. The Soul is the source of everything. You don't even exist, in reality, in the way you believe you do. You are but an emanation of the Soul. Leo does not like this, until it finally has to face its true position in the order of things. Symbolically, our Sun, what we see as the center of it all, is a small star on the far reaches of one arm of a galaxy we call Milky Way. In the scheme of things, our Sun is microscopic. If the Sun is microscopic, what does that say about the significance of Eric and Steve?
As example, you came here a few weeks ago, read the rules of what is and is not appropriate here, and then gave yourself permission to break the clearly stated rules about posting personal information by posting your own chart, even though you stated yourself in your post that you knew you were not supposed to do that. You did not ask permission, you just gave yourself a selfless-sounding justification for doing so - what you would learn from doing so would help others. In essence you put yourself first and called it serving Goddess. I'm not suggesting your desire to help others is insincere. But it is limited by unresolved issues within yourself that you would be well served to look at. And they seem to revolve around the issue you keep bringing up, and what I refer to here.
It boils down to, "who is driving the car?" Your own Soul is confused about this, is seeking resolution to its confusion. Why do you think you have a Leo-oriented chart? This is an expression of your own Soul's ponderings, grappling with the very issues you keep bringing up - who is driving the car, Soul or personality?
The answer is, the Soul is driving the car. In reality, the Soul has created
the car, and is driving it while pretending to be Eric, for purposes of its own evolution. Life begins with the inner, never with the outer. Anything Out must have a source that created it - the Source is the baseline. The manifested expression can never be the baseline.