Remember previously exported objects
If you've changed numerous assets you should be able to hit export and by default it will reexport them all to the same location as before, like Sketch's "Make Exportable" feature.
Brijean Brennan commented
Export need to remember how I last exported that particular asset that I'm exporting. I'm constantly giving me dev guy the wrong asset type because XD isn't remembering how I last exported that particular asset. Likewise, I have "web" and "ios" screens in one file and XD should remember if I exported a screen as either for web or IOS so I don't keep exporting assets at the wrong density.