I’ve found adding in spools to be rather tedious, and a way to speed this process up would be to add a “quick add” feature. So if you use the same spool type over and over, you can just hit one button and it will pre-fill all the info for you.
And to make things even speedier, you should be able to select what label type you want to use by default (A4/label), so when you make a spool, it automatically knows what label type you want to use, and opens the pdf automatically in your browser.