What is the maximum amount of time I should spend on one assignment in Essentials in Writing?

This depends on the topic and the student.

There are many different variables to consider in such a question.

Typically, a good rule to follow is: Don’t complete the worksheets/assignment sheets unless the student understands the concepts presented in the video lesson. You may need to watch the video more than once.

Then, students will complete the worksheet/assignment sheets after understanding of the new concept is evident.