Nigel - firstly, I don't have an answer for you, I'm afraid. Thankfully, our Libraries section have not thought to request this particular "feature". With any luck, they won't anytime soon
About the only thing I can add for you, though, is to say that the queue display is just a web page. So you could, theoretically, just line up a few pages as vertical columns, each pointing at a different queue. That's a possible (but rather "clunky") way of doing it. Otherwise, I imagine if you have a web dev in your team, it (probably) wouldn't be too hard for them to re-write the delivered queue station page to incorporate a number of queues on the one page?