TempControllerBase no longer threads model_params through (only the Smith subclass needs it, for its own Pot model and Kalman filters). Enable the Smith predictor's actual delay-compensated error term (theta_err now uses theta_ist_plant - theta_ist_model_delay + theta_ist_model instead of the plain plant reading), which is the correction this controller is named for. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>