Ability to scope messaging rules by listing (not property)

I want to be able to “Scope” custom messages by “Listings” not just by “Property”. This is useful to manage different configurations of the same property. Example is if a 4 bed house usually gives out only 3 rooms, and occasionally the whole 4 rooms to the guest , i want to tell them how to access the 4th room if they booked 4 rooms. But the message wont be relevant for 3 rooms. Hence the need for the ability to scope custom message by listings