How many classes will they open at once (Masters)?

When I got my Bachelor's degree, they had four classes open at a time. This meant I had almost no point where I had to wait for an assignment to be graded with nothing else to work on. I'm starting a MS CS next month. In your experience, how many classes will they let you have open at a time? The MS CS AI/ML is almost entirely PA assignments, so one at a time would mean I'd get stuck waiting for grades after every single class, so I hope it's at least two. Honestly, three or four would be ideal for me. What has your experience been like?