You are using the word "final" to mean the last person you ask or consult:
When Sola Scriptura advocates use the word "final" they mean highest; as in there are no more steps to go up: you have reached the top:
No Sola Scriptura advocate believes their interpretation is the highest authority:
So quit you little your equivocating strawman word games and just embrace the fact that God-breathed writings are as authoritative as God speaking from His Throne....and your Church is not
Better far that I should read with certainty and persuasion of its truth the Holy Scripture, placed on the highest (even the heavenly) pinnacle of authority, and should, without questioning the trustworthiness of its statements, learn from it that men have been either, commended, or corrected, or condemned, than that, through fear of believing that by men, who, though of most praiseworthy excellence, were no more than men, actions deserving rebuke might sometimes be done, I should admit suspicions affecting the trustworthiness of the whole “oracles of God.”
-Augustine, Letters of St. Augustine, Letter 82.2.5
This Mediator [Jesus Christ], having spoken what He judged sufficient first by the prophets, then by His own lips, and afterwards by the apostles, has besides produced the Scripture which is called canonical, which has paramount authority, and to which we yield assent in all matters of which we ought not to be ignorant, and yet cannot know of ourselves.
-St. Augustine, quoted from his City of God, book XI, Chapter 3,