Can Buddhist practice lead to pure consciousness experiences? First, how is &quot;pure consciousness experience&quot; (abbr. PCE) defined for the purpose of this question?

A PCE is when one’s sense of identity temporarily vacates the throne and apperception occurs. Apperception is the mind’s perception of itself … it is a pure awareness . Normally the mind perceives through the senses and sorts the data received according to its predilection; but the mind itself remains unperceived ... it is taken to be unknowable. Apperception is when the ‘thinker’ and the ‘feeler’ is not and an unmediated awareness occurs. The pure consciousness experience is as if one has eyes in the back of one’s head; there is a three hundred and sixty degree awareness and all is self-evidently clear.

Secondly, here are some self-reports by people of them experiencing PCEs. Here's one report:

Yesterday I had the first really clear and unequivocal PCE since starting with this ... previously, I had had what I call ‘mini-PCEs’. They lasted only very brief periods of time, say an hour or so, and I wasn’t really sure it was a PCE. Yesterday, however, I had no doubt at all about the experience, as it accorded in all details with what I have read about PCEs ... I had some trouble at work ... some old fears of mine concerning work, authority, success, etc. came up for me. I found myself in some turmoil about these issues and, investigating deeper into it, I once again saw the futility of a feeling-based life, a so-called ‘normal’ life of sorrow, malice, nurture, and desire ... I wrote in my journal to myself what I would do to bring about peace-on-earth, for myself and others. A little later, I sat in my chair and was still for quite awhile. The PCE experience started there and continued for the rest of the day, at times most vividly, at other times diminishing somewhat, but always lustrous, vibrant, and rich. One of the things I noticed most strongly was the intensity of sensation – the clearness and brilliance of colours, and the ability to hear every little sound around me ... at a gravel pit ... I saw a stone popping out of the ground that had some interesting features to it. I ran my hand along the exposed top of it and it felt to be alive. Similarly, the texture and surface of the stone appeared to be actually a living thing. It reminded me of psychedelic drug experiences I had when I was younger, except that it was natural and uncontaminated by any emotions of fright, fear, doubt, etc. Later on we went to the supermarket to do the week’s shopping.
Another thing I noticed about the experience was how any object, even the most ordinary and mundane, instantly had become amazingly interesting and wonderful to look at.
Everything I looked at had a life of its own. Everything appeared fresh and new.
Everywhere I looked there were sensual delights to behold. Another thing was that there was some kind of very pleasurable sensation located near the solar plexus region. I find this difficult to convey but it was a very satisfying visceral sensation. I shall have to, in future, see what I can notice about it ... I found that I could refresh the experience by running the ‘How am I ...’ question and by increased attentiveness to the feelings that contaminated the experience. A couple of times, the experience would come back in full bloom in all its lustrousness. The PCE stands out in such dramatic contrast to ordinary, every-day perception and sensation ... another key feature of the experience – no affective element, no feelings, no disturbance whatsoever – there was nothing that could disturb the experience, take anything away from it, or detract from it. In other words, there was no feeling ‘me’ to spoil the experience. How amazing.

From this juncture, I have some specific questions:

Have anyone in the Buddhist history (a relatively unknown monk perhaps) advocated pursuing such a state?
Is there any Buddhist methodology that demonstrably leads to a PCE?
In what way (in regards to consciousness) is the official Buddhist goal different from PCE?
PCE sounds very much like Eckhart Tolle's experience in his book &quot;The Power of Now&quot;, of which you can find the excerpt on this page:

“I cannot live with myself any longer.” This was the thought that kept
repeating itself in my mind. Then suddenly I became aware of what a
peculiar thought it was. “Am I one or two? If I cannot live with
myself, there must be two of me: the ‘I’ and the ‘self’ that ‘I’
cannot live with.” “Maybe,” I thought, “only one of them is real.”
I was so stunned by this strange realization that my mind stopped. I
was fully conscious, but there were no more thoughts. Then I felt
drawn into what seemed like a vortex of energy. It was a slow movement
at first and then accelerated. I was gripped by an intense fear, and
my body started to shake. I heard the words “resist nothing,” as if
spoken inside my chest. I could feel myself being sucked into a void.
It felt as if the void was inside myself rather than outside.
Suddenly, there was no more fear, and I let myself fall into that
void. I have no recollection of what happened after that.
I was awakened by the chirping of a bird outside the window. I had
never heard such a sound before. My eyes were still closed, and I saw
the image of a precious diamond. Yes, if a diamond could make a sound,
this is what it would be like. I opened my eyes. The first light of
dawn was filtering through the curtains. Without any thought, I felt,
I knew, that there is infinitely more to light than we realize. That
soft luminosity filtering through the curtains was love itself. Tears
came into my eyes. I got up and walked around the room. I recognized
the room, and yet I knew that I had never truly seen it before.
Everything was fresh and pristine, as if it had just come into
existence. I picked up things, a pencil, an empty bottle, marveling at
the beauty and aliveness of it all.
That day I walked around the city in utter amazement at the miracle of
life on earth, as if I had just been born into this world.
For the next five months, I lived in a state of uninterrupted deep
peace and bliss. After that, it diminished somewhat in intensity, or
perhaps it just seemed to because it became my natural state. I could
still function in the world, although I realized that nothing I ever
did could possibly add anything to what I already had.

I would speculate, the same as your PCE page, that this refers to what Buddhism calls jhana in Pali (same as the Sanskrit dhyana) and ch'an or zen in Mahayana traditions.
While the Sanskrit dhyana simply refers to meditation, jhana in Buddhism is defined into 8 levels - 4 lower jhanas and 4 higher jhanas. You can find more info on this in &quot;The Jhanas in Theravada Buddhist Meditation&quot; by Ven. Henepola Gunaratana.
Another two good books on this subject is &quot;Mindfulness, Bliss, and Beyond: A Meditator's Handbook&quot; by Ven. Ajahn Brahm and &quot;Mindfulness With Breathing : A Manual for Serious Beginners&quot; by Ven. Buddhadasa Bhikkhu. These two books provide the Buddhist methodology.
From Chapter 5 of Ven. Ajahn Brahm's book &quot;Mindfulness, Bliss, and Beyond: A Meditator's Handbook&quot;, obtained in PDF format from here:

As you build up mindfulness and it gets sharper, you will realize that
you are emerging from a world that has been very dim. As you get more
and more mindful, it’s as if someone has turned on the lights in the
room, or the sun has come out, illuminating the surroundings. You see
so much more of what’s around you. It’s like shining a spotlight on
reality, and you begin to see the subtle beauty of rich colors,
delightful shapes, and deep textures. It all appears very beautiful
and wonderful. When mindfulness becomes powerful, it generates not
only insight but also bliss.
When you have developed powerful mindfulness, it’s like going out into
a beautiful garden in the brilliant sunshine. It’s energizing and
inspiring. Possessing strong mindfulness, such brightness of mind, if
you then focus it on a small part of the world, then you will see so
deeply into its nature. The experience of bright and focused awareness
is wonderful and amazing! You see much more beauty and truth than you
ever imagined.

I'm not sure about Actual Freedom, but Eckhart Tolle really thought he became perfectly enlightened with this experience.
However, in Buddhism, this is nowhere close to enlightenment. This is only part of the samatha (tranquility) meditation to calm the mind, concentrate the mind and overcome the five hindrances.
Also, there are 8 levels of jhana. Actual Freedom's PCE and Eckhart Tolle's experience is probably only up to the first or second level of jhana.
The Buddha himself experienced this (first jhana) as a boy, as narrated in MN 36:

“I considered: ‘I recall that when my father the Sakyan was occupied,
while I was sitting in the cool shade of a rose-apple tree, quite
secluded from sensual pleasures, secluded from unwholesome states, I
entered upon and abided in the first jhāna, which is accompanied by
applied and sustained thought, with rapture and pleasure born of
seclusion. Could that be the path to enlightenment?’ Then, following
on that memory, came the realisation: ‘That is indeed the path to
enlightenment.’

Samatha (tranquility) is not enough. It has to be combined with vipassana (insight), to reach the enlightenment that the Buddha speaks of, as stated in Kimsuka Sutta:

&quot;Suppose, monk, that there were a royal frontier fortress with strong
walls &amp; ramparts and six gates. In it would be a wise, experienced,
intelligent gatekeeper to keep out those he didn't know and to let in
those he did. A swift pair of messengers, coming from the east, would
say to the gatekeeper, 'Where, my good man, is the commander of this
fortress?' He would say, 'There he is, sirs, sitting in the central
square.' The swift pair of messengers, delivering their accurate
report to the commander of the fortress, would then go back by the
route by which they had come. Then a swift pair of messengers, coming
from the west... the north... the south, would say to the gatekeeper,
'Where, my good man, is the commander of this fortress?' He would say,
'There he is, sirs, sitting in the central square.' The swift pair of
messengers, delivering their accurate report to the commander of the
fortress, would then go back by the route by which they had come.
&quot;I have given you this simile, monk, to convey a message. The message
is this: The fortress stands for this body — composed of four
elements, born of mother &amp; father, nourished with rice &amp; barley gruel,
subject to constant rubbing &amp; abrasion, to breaking &amp; falling apart.
The six gates stand for the six internal sense media. The gatekeeper
stands for mindfulness. The swift pair of messengers stands for
tranquillity (samatha) and insight (vipassana). The commander of the
fortress stands for consciousness. The central square stands for the
four great elements: the earth-property, the liquid-property, the
fire-property, &amp; the wind-property. The accurate report stands for
Unbinding (nibbana). The route by which they had come stands for the
noble eightfold path: right view, right resolve, right speech, right
action, right livelihood, right effort, right mindfulness, right
concentration.&quot;

So, in my opinion, a number of new age gurus have experienced the rapture (piti) and joy (sukha) of jhana and imagined that this is enlightenment, when this is only a small part of the journey towards complete enlightenment that was discovered and taught by the Buddha.
In his journey to enlightenment, the Buddha was taught by Alara Kalama and Uddaka Ramaputta as described in MN 26, and they reached the 4 higher jhanas, which is higher than what is taught by Actual Freedom's PCE or Eckhart Tolle's &quot;entering the Now&quot;, but even then the Buddha was not satisfied that this ended suffering permanently, and he continued till he achieved complete enlightenment.
The jhanas by themselves calm the mind and refine consciousness (which are impermanent), but they do not solve the problem of realizing the truth i.e. the four noble truths, the three marks of existence and dependent origination.
Samatha (tranquility) is needed to calm and concentrate the mind, while vipassana (insight) is needed to observe the nature of reality, which is not possible if the mind is not calm and concentrated.