Typically when you're working in a program and you click the close button (the "x") you are prompted to save your unsaved work. That's fine and that is exactly what Spine does. However, most programs close immediately once you click "save changes". Spine does not do this.
I guess you could consider this nitpicking, but I would appreciate it if this could be changed. The first time this happened, I was just staring at the window wondering if it's doing some serious calculations before shutdown. You can say I would have had to wait a very long time if I didn't catch on. Thank you.