1 Corinthians 11:3 does not imply inequality of nature, but order of relation. Christ is eternally from the Father (ex Patre), not in rank or value, but in origin. Just as in the Trinity, the Son proceeds from the Father without inequality. Subordination according to origin does not imply inequality of essence. The same passage says “man is the head of woman.” Does that imply women are ontologically inferior? No. It refers to a relational ordering, not a difference in dignity or essence.
Based on the above, it would appear that the point of contention isn't recognition of the order of relation. The son is clearly subordinate to the Father, as we all agree.
But in what way is salvation lost by understanding the subordination to the Father (by will of God) and not the (much more complex) 'non-created' and equality of essence of Father and son?