@Neil9 Unfortunately on Airbnb, your listing is available to book or it is not. For guests who are ready to make a reservation, if your listing is tentatively available, they will look elsewhere.
How far in advance are you comfortable accepting reservations? I perfer not to accept reservations more than 4 months in advance which is one month more than the 3 month availability setting and two months less than the 6 month setting. So what I did was set the 6 month setting and manually blocked the last two months. This requires that I free up days as they fall into the 4 month window. I do this daily. Also, I block dates that become automatically available between the 4 month and 6 month window. It may seem complicated but it works for me. Have I lost some bookings by managing my calendar that way? Perhaps, but it fits my comfort level.
You might play around with your calendar in a similar fashion, making dates you are sure you can receive reservations available and block the rest.
Hope this helps a bit!