In Falun Dafa they do talk about the mysterious pass in great detail in Zhuan Falun in Talk 4 under the section 'The Mystery of the Mandorla'. It really goes indepth about the development and positioning of the mysterious pass as well as other fascinating things:
I can't answer your question (about this light) as I don't have experience in those other practices. However Master Li Hongzhi talked about enlightenment in great detail in some of his Buddha Law Lectures, one of the methods being in Tibetan Lamaism which is called 'Light Transformation'. He goes onto describe other methods of Enlightenment in several other schools including Daoism:
“Consummation takes many different forms. As you might know, Shakyamuni taught Nirvana in order to discard human attachments to the greatest extent. In his cultivation way they didn’t even want the human body. So a person in his practice shouldn’t be attached to the human body, and should just cultivate that way. Tibetan Lamaism teaches Light-Transformation.
That is, the person sits there at the time of Consummation, and if his entire body is successfully cultivated, at the moment of Consummation his body is transformed into a beam of red light and his own Soul leaves with the successfully cultivated Buddha-Body. Since the Buddha-Body that is successfully cultivated doesn’t contain matter from this ordinary human side, human beings can’t see it, and can see only light and that a shape made of light rises up.
There are people who haven’t cultivated that well and who can’t undergo Light-Transformation of the entire body. So at the time of Light-Transformation his body instantly shrinks, “Shwa!” to a full person about one foot tall. It looks exactly like him but has been reduced to about a foot tall, with a proportionate body. That is because he didn’t cultivate enough and was not completely transfigured in Light-Transformation. There are other scenarios too. In the Dao system in China, they take the form of “deliverance from the corpse” when they Consummate.
What is “deliverance from the corpse”? In ancient China, many people practiced the Great Dao. The cultivation way of Great Dao requires that after a person succeeds in cultivation he takes the body with him—their way even wants the body. But this type of person’s flesh body is no longer an ordinary human body, for it has been completely transformed into high-energy matter and become his Dao-body. Their method of deliverance from the corpse is as follows.
The person knows that he has cultivated to Consummation and that his entire body has been fully cultivated. How is he to leave the secular world? Most Daoists don’t resolve their unfulfilled wishes among ordinary people until after their Consummation. The Buddha system isn’t like that, though, as things are resolved in the midst of one’s Consummation.
Deliverance from the corpse would stop people from looking for the person after he leaves. He will fake his death, though by that time he is in fact capable of going up to the heavens or entering into the earth. As he is about to leave, he tells his family: “I will pass away. I have succeeded in cultivation and I’m about to leave. Prepare a coffin for me.” Precisely at the time he predicted, he lays down in bed and a moment later stops breathing.
Family members see that he has passed away, so they put him in the coffin and bury him. But in fact, he has used the ability of “camouflaging”—he has used a supernormal power. What his family saw that day wasn’t his real body. So what was it? It was conjured from an object he had pointed at.
He used a shoe, a whiskbroom, a wooden pole, or a sword, and transformed it into his own image. He had pointed at an object and transformed its image. It knows how to say whatever is needed, and it says to his family: “I’ll lay down here and in a moment it’ll be over.
Just put me in the coffin, that’s all.” So in actuality, it was that piece of wood, that whiskbroom, or maybe a shoe [laying there]. The real person had left and gone far, far away. So the family buries him. After being buried, in a few hours that object will in fact return to its original form; it will return to a shoe, a bamboo pole, or a piece of wood.
That is what’s called “deliverance from the corpse.” Sometimes a person will return from somewhere else and say: “Oh, I saw so and so from your family in a really far off place. We even spoke to each other when I went there for business.”
His family will say: “That can’t be. He passed away.” That person will then respond: “I saw him. He hasn’t died. I really did see him. I even spoke with him and had a meal with him.” “That’s bizarre, he really did die.” His family knows that he was a Daoist: “Let’s dig him up and take a look, then.”
When the coffin is opened they see a shoe in there. In the Dao system there is also a form called “Ascension in Broad Daylight.” The Ascension in Broad Daylight form is used when a person’s body has been fully cultivated and he has fulfilled his wishes in the secular world prior to Consummation. It’s time for him to leave since there is nothing left to do.
At that point something called “opening of the heavenly gate” takes place; in other words, the gate of the Three Realms is opened. Then, for some a heavenly god comes to receive him, or there comes a dragon, a crane, or whatnot, on which he rides and flies away, or a heavenly chariot comes to carry him. Such things happened a lot in ancient times. There is Ascension in Broad Daylight of this sort.
In our practice system, I use the method of Ascension in Broad Daylight for those who are to go to the Falun Paradise. There are people in some cultivation ways who don’t want the body. Everything in that person’s entire paradise would be thrown into disarray if he were to be given a body. It’s just like with Shakyamuni’s Nirvana: If you were to give him a body it wouldn’t be Nirvana—wouldn’t the entire cultivation system be spoiled? His paradise is composed of the elements of Precept, Concentration, and Wisdom, and so he doesn’t want the body.”