"whom are all things" is not the same as "through whom are all things"."yet for us there is one God, the Father, of whom are all things, and we for Him; and one Lord Jesus Christ, through whom are all things, and through whom we live."
The phrase describing God is highlighted.
They indicate God as owner of all things and (just as Philo of Alexandria had for the Word) the Lord Jesus as the master builder of all things.
That does not make pre-existent Lord Jesus being God.
That does not sound right. It must not be meant in some kind if excusionary sense, ie
One God the Father not Jesus
One Lord Jesus not the Father
That sounds right to me (from the perspective of Paul).
Cordially, Bernard