First glance I would say maybe move the stack around one wall so it exits out the top above the firebox and baffle - IF that's a baffle plate I'm seeing running across just above the FB with a gap on the right side.
Is your draft 8.25 square inches? If so that seems a little smallish ... but that's just a hunch...
Otherwise it looks plausible.
Have you run the calcs on it to know if your FB, transfer opening, etc. are the right sizes?