@Andy542 Not sure you understood Colleen's question. She wasn't talking about Instant Booking as opposed to Request to book. She was talking about the difference between an Inquiry amd a Request.
If you have advance notice set, guests should not be able to enter the dates that are blocked by advance notice as a booking request, only as an Inquiry.
If they are Inquiries, you don't need to either pre-approve or decline, all you have to do is message back within 24 hours.
Inquiry- Choices are: Pre-approve, decline or message within 24 hours.
Request- Choices are: Accept or decline within 24 hours. But you can also message the guest to let them know why you can't accept and ask them to withdraw the request. If they withdraw it before the 24 hours is up, you won't have to decline.