Guesty has a feature that enables an auto-response to booking inquiries on the Airbnb messaging platform if I haven't manually responded within 30 minutes. It sends them a custom message as well as pre-approves them for booking.
This enables you to keep a high response score in case you're not able to manually respond to the potential guest.
This should be a very simple feature to add into the OwnerRez options.
Right now, the only thing you can do is an auto-responder email, which is not helpful to this need.
We are currently working on implementing Inquiry Triggers. This will allow you to set to autorespond during certain hours. If you are concerned about keep your response level high, you can have it always fire and say something like, thanks for your inquiry, we'll be with you shortly. Once inquiry triggers are out we can look at other scenarios but this would be the extent for a "v1".