A filter within the triggers for automated emails based upon if a review has been left for a particular booking.
I have automated messaging that goes out asking for a review. This filter would not send the request out if the guest has already left a review. The review could be left on an OTA or through the website.
Alternate use case:
This could also be used as a trigger to send out review requests based upon those who have not submitted a review already.
OR imports reviews automatically from Air B&B, which are linked to a booking already. Any reviews left in the OR system would be linked to a booking as well. It should (in theory) be fairly easy to see if the booking ID for the reservation shows in the reviews table, similar to the "has problem" checkbox or "Has Tags" filters