Additional Wait greetings available to support individual IVR Routes

We have recently expanded our IVR routing to send support calls to specific agents based on the potential subject of the call. 

While our customers are in each queue we wanted to be able to play a specific 'wait' greeting for each individual route with messaging specific to the subject of that IVR (e.g. provide upsell offers on an IVR routed to the sales department). 

However, it appears that we can only use 1 'Wait' greeting per Line.  

The option of forwarding each call to a separate number in the IVR and having a different 'wait' greeting for each forwarded number is not financially viable.

Have there been any other inquiries requesting to be able to assign 'wait' greetings to a specific IVR route on the same Line.

As each IVR Route can be assigned a different greeting to be played before the caller enters the queue, it would seem that being able to assign a different 'wait' message to each IVR Route would not be too difficult.

Thanks.