I'm not sure we are using the terms "relative" and "metaphysical" in the same way, because if you indeed affirmed God's total supremacy (as you did) in my sense of the phrase, "in the metaphysical sense", then you'd be affirming that you are a Determinist like me. But you're arguing against it, and it certainly is with controversy (the free will vs determinism controversy,) so I don't think we mean the same things by it.
You brought up another important issue that we can also focus on. In your quote above, I tabbed some of your key points with numbers, such as, [1], and [2]. This is so that I can address your points efficiently with my view.
[1] First, in eternity, God determined that He would be glorified. In order to accomplish this, He determined that elected men would be saved by Christ. In order to accomplish this, He determined that sinful men would be divided into elect and reprobates. In order to accomplish this, He determined that men would fall. In order to accomplish this, He determined that mankind would be created.
Then, within creation, the order is reversed. This is what we see played out. God created mankind, so that He would make them fall, so that the elect would be divided from the reprobates, so that Christ would save the elect men, so that God would be glorified.
This view is called Supralapsarianism. It shows meaning in God's plan, that it is not a cruel joke, but all in order to glorify Him. Whereas my view is God-centered, yours is man-centered.
[2] Here you teach that meaning is contingent on man gaining knowledge, but God assigns His own meanings, and if you do not accept His meanings, then you are in rebellion with Him. This is a very man-centered idea that you have here.
Now if you appeal to meaninglessness over the God that controls absolutely everything for His own purpose, you ought to deal with these views. Even if you do not agree with my views, you ought to understand it so that you can address it.