You’re pretty good at wading through things that are symbolic and things that are not and I respect your views but remember, the disciples did see him come in power and glory after his resurrection. I believe that’s what those verses are talking about but it’s in symbolic language. I don’t think he meant seeing him literally sitting on something.
Note the tremendous anxiety on the earth (due to Trib judgments) and terrifying signs in the heavens. Yes, the world in its entirety will know it is Christ. Moreover, the 144,000 and two witnesses will have preached for 3.5 years beforehand, all seen on CNN.
25“And there will be signs in sun and moon and stars, and on the earth distress of nations in perplexity because of the roaring of the sea and the waves, 26people fainting with fear and with foreboding of what is coming on the world. For the powers of the heavens will be shaken. 27And then they will see the Son of Man coming in a cloud with power and great glory. 28Now when these things begin to take place, straighten up and raise your heads, because your redemption is drawing near.”
Furthermore, there was a precursor of sorts to the Second Coming.....not the final consummation of the Kingdom when Christ sets up his Rule. This was for the benefit of the disciples only, seen in secret by them ONLY, and kept secret by the command of Jesus until after the resurrection.
Matt 16
28Truly, I say to you, there are some standing here who will not taste death until they see the Son of Man coming in his kingdom.”
Matt 17 (a small glimpse....a prequel if you will to the grandeur of the Second Coming).
1And after six days Jesus took with him Peter and James, and John his brother, and led them up a high mountain by themselves. 2And he was transfigured before them, and his face shone like the sun, and his clothes became white as light