At our institution we have about 200 courses a term that are not opened until a certain date. So those courses are all hidden until I open them. On our instance there isn't a way to open them all at once. I have to go a click the eye on each one to open them which takes a lot of time.
I'm not sure if showing/hiding a category is supposed to effect the visibility of the courses as well or not. On our instance when a category is shown or hidden it seems to be random that the containing courses visibility is effected as well. I don't know if this is from upgrading from 1.9 to our current 2.2.3 over the years.
I would like to have another button added to the category editing that will show/hide all courses within that category while still having the option to show/hide a category. Or an option when viewing all the courses within a category that you can select all courses and modify their visibility at once