CC 2017 12.0.0.81
Using the regular export menu, export an interactive PDF. That becomes the default. But now I want to export a Print PDF from the book panel, it keeps defaulting back to interactive PDF. So to make its I don't have to remember to choose Print PDF (for every single export), I have to first export a random Print PDF using the regular export menu, just to switch the default in the Export Selected files to PDF option.

The two export locations: File > Export and using the flight from the Book panel, shouldn't be tied together. They should have their own defaults.