I believe all encompassing terms like "all things" apply to specific contexts, not universally every single thing in the universe past, present, and future.
We should look at how this is used in the Bible. I like John 14:26 because it's easy to demonstrate that "all things" doesn't mean all things.
John 14
26But the Advocate, the Holy Spirit, whom the Father will send in My name, will teach you
all things and will remind you of everything I have told you.
I believe we need to apply measure and balance to these things. The Advocate didn't literally teach the disciples "all things" in the most general sense, but as far all of the things the disciples needed to know about, yes, they were surely taught all things.
Of course.
So let's see what they wrote about after being taught all things. Well, they didn't write anything about the Trinity in any clear or explicit terms for starters.
Which is not relevant since they did write all the foundations of the Trinity: 1) monotheism, 2) three distinct, divine persons, and 3) all three persons are coequal and coeternal.
So I believe Colossians 1:15-20 applies to a specific context, specifically the church. In the Bible the only thing there is an example of God creating through Jesus would be the church.
Check on Ephesians 2. It refers to the church being created. It's a parallel of Colossians 1:15-20.
14For He Himself is our peace, who has made the two one and has torn down the dividing wall of hostility
15by abolishing in His flesh the law of commandments and decrees.
He did this to create in Himself one new man out of the two, thus making peace 16and reconciling both of them to God in one body through the cross, by which He extinguished their hostility.
That's not at all the context of Col 1:15-16, just as it isn't the context of John 1:1-3 or 1 Cor 8:6. You want to argue against the meaning of "all things" in 1 Cor 8:6, but if it doesn't literally mean everything that has come into existence, then what does that say about the Father and what is Paul's point? Paul is clearly arguing against the existence of any other actual living God, stating that it is the Father "from whom are all things" and the Son "through whom are all things." So, "all things" means the same in regards to both the Father and the Son, and it means everything that ever came into existence at creation. That absolutely precludes the Son from being something that came into existence, which is an attribute of God alone. Again, my argument is sound.
And John clearly states the exact same thing in John 1:3:
Joh 1:3 All things were made through him, and without him was not any thing made that was made. (ESV)
He even explains what he means by the Word having made "all things"--"without him was not any thing made that was made." That is absolutely everything that has came into existence at creation. Therefore, the Word, as a distinct person in intimate communion and interpersonal relationship "with God," was in existence when the beginning began. So, when 1:1c states that the Word was God in nature, that is the logical outcome of 1:1a and b. That is repeated in 1:2 and fully supported by 1:3.
As for Col 1:16-17, it has nothing to do with God creating the Church through Jesus. There is simply no way to come to such a conclusion.
Col 1:13 He has delivered us from the domain of darkness and transferred us to the kingdom of his beloved Son,
Col 1:14 in whom we have redemption, the forgiveness of sins.
Col 1:15 He is the image of the invisible God, the firstborn of all creation.
Col 1:16 For by him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—all things were created through him and for him.
Col 1:17 And he is before all things, and in him all things hold together.
Col 1:18 And he is the head of the body, the church. He is the beginning, the firstborn from the dead, that in everything he might be preeminent.
Col 1:19 For in him all the fullness of God was pleased to dwell,
Col 1:20 and through him to reconcile to himself all things, whether on earth or in heaven, making peace by the blood of his cross. (ESV)
First, in verses 13-14, Paul points out that believers now belong to "the kingdom of his beloved Son, in whom we have redemption, the forgiveness of sins." Then Paul states why the Son is King of this kingdom--because "he is the image of the invisible God" and preeminent over creation. Paul then shows what it means that Jesus is "the image of the invisible God" and why he is preeminent: 1) "by him all things were created, in heaven and on earth, visible and invisible, whether thrones or dominions or rulers or authorities—all things were created through him and for him," 2) "he is before all things," and 3) "in him all things hold together."
There is simply no way to understand this as speaking of the creation of the Church. The statements are exhaustive and can only refer to, as in John 1:3, everything that came into being at creation. Notice that verse 16 begins with "For" and those that follow with "And." Those are conjunctions which
link thoughts together. That is, Paul is continuing his thought from verse 15. There is simply no way to then take verse 18, which simply states that Jesus "is the head of . . . the church," as showing that the passage is about God creating the Church through Jesus. That has nothing to do with the context.