Do Christians sin ? ABSOLUTELY, page-252

"What the some standing here see and experience, most definitely cannot be the same event as what ALL the tribes see, because only some of them standing there will see, experience it. "

You keep returning to this comparison between "some standing .." and "All the tribes ..." as if that proves they must be referring to two different events.
The two expressions are not mutually exclusive so I wonder why you seem so convinced that they are ?
I don't understand your reasoning on this, nor why the emphasis on the Mark accounts and not the others ?

Only "some are standing here .." because the others will have died by the time it happens, would be one simple explanation.
Also, "All the tribes .." is merely to indicate how universal and inescapable will be this momentous event.
BTW, it doesn't say every person in every tribe will see it ... though that also is not excluded.

We know (Biblically) that both the Transfiguration and Pentacost were separate events on their own. Neither correspond with the descriptions of the "momentous event" known as the 2nd coming and clearly it did not occur in the time frame indicated.
Why is that such a problem that Biblicists must twist, turn, pluck from here and there to pretend it either did happen or will happen ?

.