At present we have our experience set for a 24 hour cutoff in order to give us time to ensure we have proper staffing for our airbnb Experience. I know we would get more bookings if we could have a shorter cutoff or no cutoff.
I would like to suggest you add an option that an experience would remain open for booking longer if there are already some signups. In other words, we need 24 hours notice to know whether the experience is going to occur, but once we have some people signed up, we could add others up until the last minute. I suggest you modify your platform to allow this flexibility.