The 1260 days of two witnesses' testimony is in Revelation 11:3-13.
The 7th angel then sounds his trumpet in Revelation 11:15 - after the two witnesses are gone.
The 7th angel sounding announces the third woe to the inhabiters of the earth, based on Revelation 8:13.
Revelation 12:12 after the war in the second heaven, which Michael and his angels cast Satan and his angels down to earth,
12 Therefore rejoice, ye heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.
Why do you disregard what it says in Revelation 12:12 - Woe to the inhabiters of the earth ?
In Chapter 6, Jesus removed the seals on the scroll. The scroll was opened to reveal what would take place in the 7 years leading up to Jesus's return. Chapter 13 are events in the second half of those 7 years.
The first part of chapter 11 is a parenthetical explanation of the 7th Trumpet. Chapter 10 is a parenthetical describing the 7th Trumpet. Chapter 12 is a parenthetical.
The 7th Trumpet sounds, and the only chronological narrative is that Jesus is declared King of the 7th Kingdom.
Revelation 13 is the third woe.
If the 2 witnesses were part of the chronological narrative of the first 6 Trumpets, they would have been seen in Revelation 7 along with the 144k. The 2 witnesses parallel the events of Revelation 13. The 144k parallel the events of the Trumpets and Thunders.
The 2 witnesses are not in the the first 6 Trumpets, nor the 7 Thunders. The 144k are on the earth during the first 6 Trumpets, and the 7 Thunders. So is Jesus and the angels as they came to earth at the 6th Seal. The final harvest covers the events of the first 6 Trumpets and 7 Thunders. The final harvest is described in Matthew 13 and 25.
The first 2 woes are mentioned with the 5th and 6th Trumpets. Those woes carry in to the 7 Thunders. The last half of Revelation 10, then begins to explain the 7th Trumpet. The 7th Trumpet is explained as the time of the 2 witnesses.
Then the chronological narrative starts back up with:
"The second woe is past; and, behold, the third woe cometh quickly."
The 2 witnesses were not part of the chronological narrative, but a parenthetical.
The second woe was past, way back in chapter 9 prior to the 7 Thunders. So the chronological narrative stopped when John was told not to write about the 7 Thunders. Jesus was redeeming the nations one soul at a time during the the first 6 Trumpets and the 7 Thunders. Now when the 7th Trumpet sounds, that work is finished. They are now become the kingdoms of Christ.
In the midst of the week of the 7th Trumpet, which is a set of days, as written in Revelation 10, "the days of the 7th Trumpet", Jesus will either hand the kingdom over to Satan for 42 months. Or the winepress of God's wrath will destroy the rest of humanity, and Satan will be bound in the pit at the end of the the week of days.
The confirmation of the Atonement Covenant is to determine if there is any left on earth at that point to be redeemed. The Covenant still covers those beheaded, only if there are any that will be beheaded. Only God can say at that point who will be beheaded, or if no one will be beheaded in the next 42 months.
"But the court which is without the temple leave out, and measure it not; for it is given unto the Gentiles: and the holy city shall they tread under foot forty and two months."
At this point there will not be any of Jacob's offspring on the earth, except the 144k with Jesus. Only Gentiles will be left, and not even that many. More than show up at Armageddon 42 months later. The 144k leave with Jesus to mount Zion, when Satan is allowed to be the 8th kingdom. Many will be killed during the next 42 months, because of human wickedness and greed. Many will be beheaded, because that is the only reason why time is extended. The Gentiles mentioned in that verse will have the mark, and be following Satan's desires. No one will be redeemed waiting for the battle of Armageddon to be raptured. The only souls redeemed during this 42 months will be those beheaded, and they will have to wait to receive a body, until after Satan is bound in the pit. The 144k already have a redeemed body, because they wait with Jesus on Mount Zion. Those souls harvested during the final harvest have a physical body then, as they return on horses to start the Millennial Kingdom. They are those waiting on the sea of glass.
In Revelation 12 the wilderness is symbolic in keeping with the historical narrative of the OT, however why would there be both a physical wilderness on earth and this sea of glass not on earth. The final harvest would be physically waiting on the sea of glass. The wilderness is symbolic of this sea of glass. The sea of glass is not on the earth, because John describes it in heaven prior to the Seals being opened.