Upvote:2
There are already multiple answers surrounding this doctrine. This answer summarizes them:
In regards to Hebrews verse the Church of Jesus Christ of Latter-day Saints believe that the God of the Old Testament is Jesus, and there is no other like Him (savior).1 Quote from linked answer:
And it is consistent that there is no other like God. No other Gods concern us. We worship God our Heavenly Father only, and subject ourselves to His will. No other god, "as there be gods many," is of concern to us.
Similarly the Isaiah verse iterates a similar doctrine. Man becoming gods does not replace/reduce God, He is always our God.2 See this answer which answers the Isaiah 43:10 specifically
1 this answer, Why do Latter-day Saints believe that Jesus Christ was Jehovah of the Old Testament?