Queue Visual Indicator

I am trying to get a visual indication if there are calls waiting in a queue on Aastra 9133i phones.

We currently have a Nortel BCM system that flashes a button when there are people waiting in our call queue. This lets our agents know if they need to hurry up on their phone calls.

So I aimed to get the same type of functionality from asterisk. I first tried to use metermaid with a Hint similar to what can be done with a parked call. If I do a “show hints” I can see that the call queue always shows State:InUse regardless of any agents being logged in or any calls in the queue.

My next idea was a bit more ugly. I have already tweaked the second example from Agents Without Channel to work properly for me. My thought was to use Devstate from Bristuff then count incoming calls vs. answered calls. I thought about this for a few seconds before discounting this as a solution.

So, has anyone attempted to do this before? All I can find about BLF references extensions, parked calls with metermaid.