I agree wholeheartedly that white supremacy has been an important component of capitalism throughout its historical development. However, it's pretty easy for me to imagine a world in which capitalism exists without white supremacy. The extraction of surplus value from labor works fine without racial distinctions; there are plenty of other ideological tricks to justify capitalism exploitation (e.g., the myth of the autonomous individual, as you noted). Thus I wonder if white supremacy is indeed a necessary and inescapable precondition for any capitalist society.
Miles