Can you open up lessons for multiple sections at the same time??
Not that I know of, but you can do it relatively easily from within the unit. When you go to the unit, on the top you can see the list of your sections and an Assign to section button. You can choose your section from the dropdown list and click on the Assign to section button.
You can then switch between sections using the same drop down menu and open up the lessons. I don’t know of any other easier way of doing this.