Yes and I think in your case that is desirable. That is the only way how to make the queue making 6 seconds delay between the entries. But currently it actually stops all the queues as we only have one thread that processes all the queues as you can see in the request Workqueue - implement round-robin processing. So not a big win for you anyway.
We have many thoughts on queue improvements and we should really start a topic on this. I will do it.
EDIT: Actually there is one: Work Queue Improvements. We should start putting the ideas there.