Agreed. But I believe only the firstfruits "barley" of the Messiah's resurrection is in heaven right now in resurrected bodies with his like a tithe; at least the 24 elders are there presently. Now, exactly who they are, I have no clue...but I don't believe any other OT saints (like King David for instance...if we can even call him a saint) are in heaven just yet because of the passage below.
I'm assuming that you don't believe all of the Old Testament saints were raised and went up with Christ because Matthew says "many of the saints..."
(Mat 27:52) And the graves were opened; and
many bodies of the saints which slept arose,
(Mat 27:53) And came out of the graves after his resurrection, and went into the holy city, and appeared unto many.
But look at the EXACT WORDING of those verses Yahshua. It says that many of the saints that slept rose
AND came out of the graves,
AND (extreme emphasis on this AND) went into the holy city
AND appeared unto many. The MANY (not all) of the saints describes those who did ALL FOUR of things. To be sure, the wording of those verses DOES NOT tell us that only SOME of the Old Testament saints rose, it tells us that out of those saints that were raised, SOME of them went into the holy city and appeared to many.
Why did only some of them go into the holy city? We don't know for sure because we are not told, but we do know that not every saint who died, died in the vicinity of Jerusalem. It also could be that SOME of the saints went to other cities in Israel as a witness of God fulfilling His promises. Like I said, we are not given the reason but there are many reasons why ALL of the saints didn't go into Jerusalem.
We have the same thing in Daniel 12. MANY of THEM ( them being everyone who sleeps in the ground), will awake, some to everlasting life (saints) and some to everlasting contempt (not saints). But there is ANOTHER group that sleeps in the dust, and that group is the Giants or Nephilim. There is no resurrection for them, the resurrection is for humans only.
Dan 12:2 And many of them that sleep in the dust of the earth shall awake, some to everlasting life, and some to shame and everlasting contempt.
No matter if Daniel 12:2 was in the past as I believe, or if it's in the future as you believe, MANY is a problem lol. In your view that means that not EVERY HUMAN BEING will be raised in the future resurrection where the just and unjust will be judged.
Also Yahshua we have to keep in mind Pro_25:2, It is the glory of
God to conceal a thing: but the honour of kings is to search out a matter.
The literal EXACT reading of those two passages reveals the truth about the resurrection. This is getting long, so I'll respond to the rest of your post in a separate reply.