I don’t really ever use the queue, but I thought about a way it could be really useful: Have it trigger before workshop automation. Once you get to the point in the run where most things are capped there are generally a few that use iron/minerals/wood that you do have enough storage for but not the production to get it before the next automatic time crunch by the chronofurnace. The queue would be perfect for building these, there is a split second when it shows you have enough resources and sometimes you can click on it then, but mostly you have to turn off the automation, combust a tc, then buy the building, then turn back on the automation.
I think the idea for the queue came from other idle games, maybe Evolve idle, and there is one thing it does better: an option to allow any building in the queue to get build regardless of order. That would be cool too.
It is easier coding-wise to have it only trigger the first item in the queue but when I play Evolve I almost always have it set to do anything in the queue and I use the queue to build houses and stuff, rather than clicking it whenever it is buildable. To encourage this behavior, rather than using the massive dropdowns have it so you can use a hotkey to click and add things to the queue.