Thanks for your thoughtful response.

On your first point, I thought that reabsorption occurs at Enlightenment, which frees that consciousness from the need to reincarnate. It would not therefore be something that happens at death. If that were true, it would be hard to see how some children have past-life memories; it seems that they do.

“Why did the Unity differentiate itself into Being in the first place?” That's a great question, which would require a long essay, which I don't feel up to. But I recommend the ideas of Bernardo Kastrup on that theme.

Yes the observer is “at the end of the day, simply Consciousness itself — The Ground of Being”. The key phrase there is “at the end of the day”, but it's a very long day. As you point out, there is much in between. And obviously in our everyday existence we do not experience ourselves as this Ground of Being.

It's a good idea to have an enquiring mind and veer away from all orthodoxies. I of course agree with you that there is much of value in Buddhism, and that the Tibetan version is especially important.