It doesn’t follow—even if we were aware of his existence we would still be free to choose whether or not to commit ourselves to his worship or to abide by his expressed will.

Certainly true, and validated by the Bible itself. Adam, Moses, Abraham, and Lucifer himself all had direct knowledge of God's existence. This did not prevent them from being disobedient (Adam, Moses at the rock), from arguing with God (Abraham), or from actively rebelling against his rule (Lucifer).

Conclusion: either none of these characters had free will or free will is not compromised by direct knowledge of God's existence.