When discussing the Subdivision Surface modifier the Render amount is neglected. It should be noted that this is an important value. Some issues I have had with my renders not matching what the viewport showed, was because the viewport number was higher than the render number. Ensuring to mention that the render number can crash the computer just as easily as the viewport number can.
Would also suggest moving the quick discussion of the modifier order to right before adding the mirror modifier.
Modifiers are a huge topic and it might even stand to have a lesson at the video touching on the various ones and the most used. This would help keep the lesson video focused on the topic.