Evidently you did not notice that James placed the raising of the fallen tent of David in the future. At Acts 15:16 James quoted the prophecies of Amos. James quoted from the Greek version of the OT (the
Septuigant), but with a slight modification. Here are the verses from the Septuigant :
"In that day will I raise up again the tabernacle of David that is fallen down; and I will build again the ruins thereof, and I will set it up...That the residue of men might seek after the Lord, and all the Gentiles, upon whom my name is called, saith the Lord, who does all these things" (Amos 9:11-12; Septuigant).
James replaced the words "in that day" with the following words:
"After this I will return, and will build again the tabernacle of David, which is fallen down; and I will build again the ruins thereof, and I will set it up: That the residue of men might seek after the Lord, and all the Gentiles, upon whom my name is called, saith the Lord, who doeth all these things" (Acts 1516).
James believed that this prophecy of Amos will not be fulfilled until after the Lord Jesus returns. And of course James was correct.
Your conclusion that James changed the wording is off.
You see this...
Acts 15:15 And to this agree the words of the prophets; as it is written, 15:16 After this I will return, and will build again the tabernacle of David, which is fallen down; and I will build again the ruins thereof, and I will set it up: 15:17 That the residue of men might seek after the Lord, and all the Gentiles, upon whom my name is called, saith the Lord, who doeth all these things. 15:18 Known unto God are all his works from the beginning of the world.
James used the word "prophets" which is plural.
In other words, he was basing his assertion on more than one prophet.
Thus, his "After this" is in connection with what another Prophet had also said about that.
Take a look at what Hosea had said about Israel's latter days.
Specifically, the first word in verse 5, but here is the entire chapter for scope and context, which; not surprisingly; agrees with Paul's citing of Hosea in his Romans 9 assertion that God is not through with Israel, rather, that He is doing something else first "As he saith ALSO in Osee..."
Anyway, take a look at the first word in verse 5, below - it is why James mentioned "prophets" plural.
Hosea 3:1 Then said the LORD unto me, Go yet, love a woman beloved of her friend, yet an adulteress, according to the love of the LORD toward the children of Israel, who look to other gods, and love flagons of wine. 3:2 So I bought her to me for fifteen pieces of silver, and for an homer of barley, and an half homer of barley: 3:3 And I said unto her, Thou shalt abide for me many days; thou shalt not play the harlot, and thou shalt not be for another man: so will I also be for thee. 3:4 For the children of Israel shall abide many days without a king, and without a prince, and without a sacrifice, and without an image, and without an ephod, and without teraphim: 3:5 Afterward shall the children of Israel return, and seek the LORD their God, and David their king; and shall fear the LORD and his goodness in the latter days.
While I'm at it, here is Paul in...
Romans 9:22 What if God, willing to shew his wrath, and to make his power known, endured with much longsuffering the vessels of wrath fitted to destruction: 9:23 And that he might make known the riches of his glory on the vessels of mercy, which he had afore prepared unto glory, 9:24 Even us, whom he hath called, not of the Jews only, but also of the Gentiles?
Hosea had ALSO prophesied a time when God had spoken of a delay in His plans for Israel during their disobedience, while He did something else first.
Thus, that He was once more delaying His plans as to Israel during Israel's disobedience in Paul's day, was not unheard of; was not out of line with God's practices in the past.
In this, Romans 9:25 is not about Romans 9:24, rather, it is the same thought as verses 22 & 23.
Hosea had also prophesied a delay, in his day, not a cancellation, which is what the following is actually talking about.
9:25 As he saith also in Osee, I will call them my people, which were not my people; and her beloved, which was not beloved. 9:26 And it shall come to pass, that in the place where it was said unto them, Ye are not my people; there shall they be called the children of the living God. 9:27 Esaias also crieth concerning Israel, Though the number of the children of Israel be as the sand of the sea, a remnant shall be saved: 9:28 For he will finish the work, and cut it short in righteousness: because a short work will the Lord make upon the earth. 9:29 And as Esaias said before, Except the Lord of Sabaoth had left us a seed, we had been as Sodoma, and been made like unto Gomorrha. 9:30 What shall we say then? That the Gentiles, which followed not after righteousness, have attained to righteousness, even the righteousness which is of faith. 9:31 But Israel, which followed after the law of righteousness, hath not attained to the law of righteousness. 9:32 Wherefore? Because they sought it not by faith, but as it were by the works of the law. For they stumbled at that stumblingstone; 9:33 As it is written, Behold, I lay in Sion a stumblingstone and rock of offence: and whosoever believeth on him shall not be ashamed.
Thus, in agreement with you Jerry, James is not only asserting his understanding that Israel's promise has been delayed once more, but that...
"Known unto God are all his works from the beginning of the world" Acts 15:18.
They've been thrown off by the change Paul has laid out the details of to them about, but have decided to trust that God knows what He is doing.
As had been their response in the following, as well.
Acts 11:15 And as I began to speak, the Holy Ghost fell on them, as on us at the beginning. 11:16 Then remembered I the word of the Lord, how that he said, John indeed baptized with water; but ye shall be baptized with the Holy Ghost. 11:17 Forasmuch then as God gave them the like gift as he did unto us, who believed on the Lord Jesus Christ; what was I, that I could withstand God? 11:18 When they heard these things, they held their peace, and glorified God, saying, Then hath God also to the Gentiles granted repentance unto life.
Mid-Acts Dispensationalism - what a wonderful set of Bible based principles for understanding the Scripture!