In the video for this section (which is great because it explains how the formulas work, btw), using a boolean to tell the system to calculate using a different value is called a "best practice."
Why?
Specifically, as I see it, the boolean creates an entire line item full of cells which need to be referenced every time the total is calculated. Wouldn't it be more efficient to change the formula in the "Final Forecast" row to "IF Override Forecast > 0, THEN Override Forecast, ELSE, Initial Forecast"?