Normally, I just set these settings to unlimited posts. However, there can be good reasons to limit the number of posts per day or even disable them entirely. Fewer posts per day can help encourage posters to focus on quality rather than quantity. Or it could simply make your life as a mod easier. Fewer posts per day = less to review and approve. No posts per day is good if you’re the only mod and you’re taking a break, or you want to keep a stream frozen in time for whatever reason.
Ultimately, if you own a stream it’s up to you! :)