In Ferefman's paper 'Is the Continuum Hypothesis a definite mathematical problem?', he argues that within the philosophy of conceptual structuralism, the continuum hypothesis is not a definite mathematical problem.

However, Koellner wrote a response to this paper in his paper 'Feferman on the Indefiniteness of CH'. In this, he proposes that it is possible to reach the conclusion that the continuum hypothesis is a definite mathematical problem via conceptual structuralism though he presents no argument for it. Instead, he relates this to the views of Martin and Isaacson.

Does anyone know where I can find an argument that the continuum hypothesis is a definite mathematical problem by the view of a conceptual structuralist?