It is part of reincarnation to loose the lower ego / consciousness part of the soul and you get a new one, and this can connect to your higher consciousness by meditation and Gods will that has all the memories and such.
Levels above immortality is just, we don't know, at least I don't, there is no and likely will not be many information on these levels publicly available. I would say it's very unlikely that they can retain their lower consciousness, but it is very likely that they can connect to their higher consciousness way more easily.
So, I have a doubt. I’m practicing a meditation to enhance my memory, to make it much more efficient and help me learn more things.
For example, right now I’m studying electrochemistry, and the process I use is quite unusual. During the meditation, sometimes old pains or inner struggles resurface, but afterwards I notice real improvement. It works, but it’s a very particular process.
In my view, it even resembles the process of reincarnation, as described on the Magnum Opus website. It feels like it awakens hidden fears, and yet this is what makes it effective in a very unique way.
The only thing is that I still don’t fully understand why this happens.