Hi, all, I've committed a major update to the new-to-2.4 "Cancel Background Process" code. You'll find this on the Document menu after you initiate export (assuming you haven't disabled background export). It seems to work pretty well now, thanks to Scott's testing, but there are likely still some issues. Please test, if you can, and let me know of any difficulties. The biggest would be an uncaught exception (we need to use exceptions here to escape from deeply nested calls), but I'm pretty sure that's not going to be an issue. Smaller problems might arise from changes in the return values of some calls of which I failed to take account. Scott ran into one of these, so I hope I have them all now, but you never know....
One polishing thing I've considered is to allow this to be done by clicking on the spinning wheel thing that pops up during compilation (or maybe double clicking), and possibly to bind this to some key. Any thoughts? Riki