The dynamic performance of a fully automatic real-time optimization (RTO) scheme is evaluated for a reactor-separator-recycle process in mode I (minimize column boilup at given throughput) and mode II (maximize production) operation. In both modes, the reactor composition set point is the optimized unconstrained degree of freedom. The RTO requires a simple override control scheme to reconfigure the inventory loops as the active constraint set changes between mode I and mode II. The overrides reorient inventory loops from in the direction of process flow (CS I) in mode I to opposite the process flow (CS II) upstream of the bottleneck constraint (column maximum boilup), limiting mode II production. The set of selected signals in the override scheme allows automatic distinction between mode I and mode II optimization. Closed loop results are reported for realistic sustained disturbance scenarios that include sudden fast changes as well as gradual equipment degradation. The RTO scheme significantly improves economic performance with up to 9% and 7% benefit over constant set point operation in mode I and mode II, respectively. Also, economic loss compared to the optimum gold standard is within 1%, implying excellent performance even as the plant is never truly at steady state.