Yes, they are! For a limited time, questions in the Beta subjects do NOT reduce the remaining question count for your billing cycle.
For example, let’s say you have 30 homework questions for the month. You can ask as many questions as you want in the new subjects and you’ll still have 30 homework questions remaining. (Non-Beta subjects will still reduce your questions remaining.)
Please note: Response times vary by subject and question complexity. Median response time is 34 minutes and may be longer for new subjects.