In my Facebook group "Dharma Connection" there happens to be many Dzogchen practitioners around so I posted this as it may interest them as I think it may also interest you as a reader. I've also posted some comments by Thusness below. (note: Thusness is not a Dzogchen practitioner so whatever he said need not be indicative of Dzogchen, just the practice and experience between us)
Thusness said to me:
"As I suspected (thumbs up) I mean the rainbow body. That can only be done after realization of twofold emptiness and intensity of luminosity into the three states (waking, dreaming, deep sleep)... you are doing pretty well. The integration has been progressing well of the non-dual bliss into your deep sleep state, in view of the short period after your realization of anatta. The inner core must completely disappear and the intensity of luminosity must heighten... Sensations will become transparent and crystal sharp clear.
At present the core center is gone... You write too much and have too little rest. Your mind must have enough time to rest in non-conceptuality of the 6 entries and exits. Otherwise it will not be easy for you to penetrate further. After realizing the twofold emptying there is no more boundaries between mind, appearances and apparent objects and experience becomes seamless... All is mind or this integrated activity. Then we should actualize and integrate this realization.
In touching, both subject and object are both emptied and deconstructed into a single activity of touch and the intensity of luminous clarity must be strong... is it strong now? Or just like passing thoughts with no intensity.
Now penetration of the 3 states is only supported by the strength of your view and realization, not by the intensity of your non-conceptual experience.
"In essence rainbow body is a realization..." Maybe actualization of realization (would be better), in essence it is an actualized state."
my comment: Dzogchen practitioners use the term 'Realization' differently than I and Thusness, 'Realization' could mean something like full actualization or Buddhahood for them and not just an initial insight/recognition/experience.
"I believe Malcolm Smith, Many texts state the "physical body reverts to the essence of the elements as rainbow light and disapears." Also there is a great deal of writing by many such as Longchenpa that describe the difference between the "vanishment of the physical body" between trekchod, rainbow body as "jalus" and "phowa chenpo" the Great Transfer. This is the goofiest of Malcolm's posts that I have ever read... Am I missing something?"
"Rainbow body where the body shrinks and disappears is a sign of incompletely finishing the fourth vision in this life."