I don't get it. I haven't read most of the folks you mentioned, just Don Juan a long time ago, which was very handy as I needed a Language to relate to others from my own experience..... which had a language that nobody I came across knew, so using Don Juans Language helped make it possible to talk about...... "sorcery" to folks interested. But this "Immortality", I don't get.
We are All Immortal.... so what is the need to seek it, we can't avoid it.
Does this mean staying in the same physical body and life....no thanks, that is counterproductive..makes evolution more difficult.
My first memories in this life, before I could even talk, were of past lives.
I have relationships with folks in this life that I shared past lives with, that remember those lives as well or better than I do.
I once met a guy, a wizard of sorts....who in this life in his youth, was present in my past life, the day I died (was killed by Chinese soldiers).... He remembered those moments better than I did, as he wasn't Blocking things that were very uncomfortable.
So he was able to teach me a lot, (that took me years to assimilate), because he was seeing it more clearly and hadn't blocked the most pertinent things as I had done.
So, we are immortal....
Learning to die to gain the most evolution was primary to my teachers teaching..... and my learning.
I mean immortal is sort of a relative term really, because what is it that we want to be immortal, what is it that we believe we want to be immortal.
Cause you see our evolution is circular, and though after thousands of years it does have what appears on one level to be an "end" point....that end point is like....hmm, like an archetype, a seed to a new beginning.
So yeah, we can carry on in a body for thousands of years,(changing skins periodically) and also transcend that for a length of time if we make that choice...and live more in an energy body..... but you know, thousands of years is pretty good..... But if we look beyond the physical and even energetic existence that we call us....... beyond that which we cling to .....and clings to us for thousands of years....something else goes on beyond that....and it all recirculates basically for eternity.
It should be noted though that "eternity" is also a mis-leading term, as the reality is ...... hmm, eternity is really like a chain of connected eternities. Some religion calls them Yuga's I believe.
You could say that an eternity is an incarnation of God....
but just like us
God Reincarnates....
so each life of God is another eternity.
And from what I've "seen".... our old selves carry over, sort of like pieces in the NEW DNA of the new Eternity.
Now I really dislike using that term,"God", because almost all of the ideas about that in mass consciousness....are way off the mark. Nevertheless it's the best way of describing it that I have.
So I am not sure what you refer to when speaking of seeking immortality......?