I would offer an opinion from another camp (Amil) .
One thing that it does not say which we are informed of in the opening of the book is that not only was the vision inspired but also signified. Revelation 1:1 Giving it the understanding as the mystery revealed, even before it is used in the parable found in chapter 20 six times .
I would think it could violate how we hear if one time literally and the other in parables. That would seem to bring confusion not restoration as the peace of God.
I do not think the church which is in tribulation even today (last days) from the beginning of the time of reformation (Hebrews 9)
I don’t see those persecuted for Christ disappearing for a literal thousand years?
The passage “a seal upon him, that he should deceive the nations no more” is in respect to the results the past. . . the time of reformation, the beginning of the l
ast days. Up until that time he deceived all the nations that they must get under the Law of Moses. The letter of the law “death”.
When the time of reformation, the lasts days came, the 70 foot high veil was torn from the top down to the bottom to represent the temporal flesh of Christ. (the shadow of circumssion )
There was no Jewish man sitting in the holy of holies .The faithless Jews that demanded they have a king because of their jealousy of the surrounding pagan nations came to end .Satan fell .the gospel was preached to all nations that we serve a unseen God who is not served with human hands .In that way we have the treasure of that power that works with us but not of us.
It would seem he will be loosed for a short period to build another abomination of desolation .(temple built with human hands) . .then comes the last day like a thief in the night.
Acts 2:15-17 King James Version (KJV) For these are not drunken, as ye suppose, seeing it is but the third hour of the day. But this is that which was spoken by the prophet Joel; And it shall come to pass in the
last days, saith God, I will pour out of my Spirit
upon all flesh: and your sons and your daughters shall prophesy, and your young men shall see visions, and your old men shall dream dreams:
The bible uses the words last day .Six times in John to emphasize .it is the end of the world under the Sun, the door to the resurrection is closed.
Thousands years would seemed to be defined by first three usages ( three denotes the end of a matter).
Psalm 90:4For a
thousand years in thy sight are but
as yesterday when it is past, and as a watch in the night.
Ecclesiastes 6:6 Yea, though he live a
thousand years twice told, yet hath he seen no good: do not all go to one place?
2 Peter 3:8 But, beloved, be not ignorant of this one thing, that one day is with the Lord as a
thousand years, and a
thousand years as one day.
If the thousand years in Revelation 20 are literal then every time the word thousand come up it must also be. Not a salvation issue. More of what I would say as you offered (1 John 2:27) a great warning helping us in our tribulation making the load lighter yoked with him . He will come as a thief in the night.
https://classic.biblegateway.com/passage/?search=John+6:39&version=KJV
Last day
John 6:39 And this is the Father's will which hath sent me, that of all which he hath given me I should lose nothing, but should raise it up again at the
last day.
John 6:40 And this is the will of him that sent me, that every one which seeth the Son, and believeth on him, may have everlasting life: and I will raise him up at the
last day.
John 6:44No man can come to me, except the Father which hath sent me draw him: and I will raise him up at the
last day.
John 6:54 Whoso eateth my flesh, and drinketh my blood, hath eternal life; and I will raise him up at the
last day.
John 11:24Martha saith unto him, I know that he shall rise again in the
resurrection at the
last day.
John 12:48He that rejecteth me, and receiveth not my words, hath one that judgeth him: the word that I have spoken, the same shall
judge him in the
last day.