I don't see how this post changes anything of what was said in the post you quoted.God does not have a right hand. God is an invisible Spirit which no man has seen nor can see. The 'right hand of God' is a metaphor for the place of heavenly power and authority. Stephen didn't see God with Jesus standing at his right hand when he looked up to heaven.What he saw was Jesus in the position power and authority in heaven.
Matt 28:18 And Jesus came and said to them, ‘All authority in heaven and on earth has been given to me NRSV
Jesus is in a position of authority BECAUSE GOD placed him there.