I think if you want the "mechanical" view, from what I can see it's basically a reading of the violet ray, with the inclusion of the lower rays for the negative path.
A soul can only incarnate when there is an opportunity for the manifestation of a body and so you have souls which are closest to being harvestable being able to "jump the queue" due to their conscious awareness of their need to evolve. There are some who may not choose to do this as well and continue in another manner. I think you are along the right lines that those entities are likely consciously involved in this choice.
Quote:54.30 Questioner: I’ll make this statement which may be somewhat distorted and let you correct it. We have, coming through the feet and base of the spine, the total energy that the mind/body/spirit complex will receive in the way of what we call light. Each energy center as it is met filters out and uses a portion of this energy, red through violet. Is this correct?
Ra: I am Ra. This is largely correct. The exceptions are as follows: The energy ingress ends with indigo. The violet ray is a thermometer or indicator of the whole.
34.16 Questioner: Would the red ray, an intense red ray, then be used as an index for seniority, the seniority system of incarnation, as well as the intense violet ray?
Ra: I am Ra. This is partially correct. In the graduation or harvesting to fourth-density positive, the red ray is seen only as that, which being activated, is the basis for all that occurs in vibratory levels, the sum of this being violet-ray energy.
This violet ray is the only consideration for fourth-density positive. In assessing the harvestable fourth-density negative, the intensity of the red as well as the orange and the yellow rays is looked upon quite carefully as a great deal of stamina and energy of this type is necessary for the negative progression, it being extremely difficult to open the gateway to intelligent infinity from the solar plexus center. This is necessary for harvest in fourth-density negative.
A soul can only incarnate when there is an opportunity for the manifestation of a body and so you have souls which are closest to being harvestable being able to "jump the queue" due to their conscious awareness of their need to evolve. There are some who may not choose to do this as well and continue in another manner. I think you are along the right lines that those entities are likely consciously involved in this choice.