BTW, you might be able to save yourself some trouble by just taking a bit of time to study the graphs that I included in my write-up, in particular Fig. 2 and 3. They show (and I described) exactly what you attempted to illustrate, i.e., the similarities and differences between the impulse-response model and the Performance Manager approach when the input function changes in a square-wave manner (albeit as a step up, not as a step down as you modeled).