So you are differentiating David's throne and the Throne of God.
QUESTION: Are you speaking of a physical throne of David (hidden somewhere in Israel)
...or a symbolic throne (one holding the position and full authority of David)?
The authors of the NT were quoting passages from the OT to support the full authority and kingship of Jesus.
They quoted these OT passages to indicate where Christ was sitting, at "God's right hand."
Peter was convinced that Jesus received the promises and he preached that message to the Jews of every nation at Pentecost (Acts 2:29–33).
Peter's message to the Jews was that Jesus fulfilled these promises.
“Brothers, I may confidently say to you regarding the patriarch David that he both died and was buried, and his tomb is with us to this day.
So because he was a prophet and knew that God had sworn to him with an oath to seat one of his descendants on his throne,
he looked ahead and spoke of the resurrection of the Christ, that He was neither abandoned to Hades, nor did His flesh suffer decay.
It is this Jesus whom God raised up, a fact to which we are all witnesses.
Therefore, since He has been exalted at the right hand of God, and has received the promise of the Holy Spirit from the Father, He has poured out this which you both see and hear. (NASB 2020)
Revelation 22:16 I, Jesus, have sent My angel to testify to you of these things for the churches. I am the root and the descendant of David, the bright morning star.”
Rob
Here is a little logic. It is a story about a near kins person sitting on David's throne without it ceasing to be David's throne or this person sitting at the king's right hand not sharing in the rule of the kingdom.
18 And Bathsheba said, Well; I will speak for thee unto the king.
19 Bathsheba therefore went unto king Solomon, to speak unto him for Adonijah. And the king rose up to meet her, and bowed himself unto her, and sat down on his throne, and caused a seat to be set for the king’s mother; and she sat on his right hand.
24 Now therefore, as the LORD liveth, which hath established me (Solomon), and set me on the throne of David my father, and who hath made me an house, as he promised, Adonijah shall be put to death this day.
The throne of David was in Jerusalem
It remained the throne of David after David died
It was the throne of David when his son Solomon was sitting on it
There was not a co-rule when someone temporarily sat on his throne at his right hand.
The throne of David has never been in heaven.
The throne of David is not at the right hand of the Father.
Jesus Christ is temporarily sitting on the Father's throne in heaven at his right hand, a place of honor but not of sovereign rule but to intercede for others to the God as Bathsheba did to Solomon for Adonijah.
Lu 19:11 And as they heard these things, he added and spake a parable, because he was nigh to Jerusalem, and because they thought that the kingdom of God should immediately appear.
12 He said therefore, A certain nobleman went into a far country to receive for himself a kingdom, and to return.
34 For David is not ascended into the heavens: but he saith himself, The LORD said unto my Lord, Sit thou on my right hand, (temporarily - see next verse)
35 Until I make thy foes thy footstool.
36 Therefore let all the house of Israel know assuredly, that God hath made that same Jesus, whom ye have crucified, both Lord and Christ. (but not King on David's Throne yet)
18 But those things, which God before had shewed by the mouth of all his prophets, that Christ should suffer, he hath so fulfilled.
19 Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from
the presence of the Lord;
20 And he shall send Jesus Christ, which before was preached unto you:
21 Whom the heaven must receive until the times of restitution of all things, which God hath spoken by the mouth of all his holy prophets since the world began.
The plan is for Jesus to return to earth to establish his physical and literal kingdom and to rule as King over all the nations from Jerusalem where David's throne is.
Here is a tidbit for you. In the Psalms there are 12 prayers in 12 different Psalms to our Lord from his people Israel to "arise" and save them from the enemy, who we learn is the antichrist. In only one of those prayers does the Lord speak and then just in one verse. It is in Ps 12:5. Here is what he says;
Ps 12:5 For the oppression of the poor, for the sighing of the needy,
now will I arise, saith the LORD; I will set him in safety from him that puffeth at him.
He is speaking of arising from the Father's throne where he has been sitting since he ascended in Acts 1.