How can I convert my custom setting's files from Exposure 4 to Exposure 5? Do I have to recreate all of them in Exposure 4?
The settings should automatically be converted and imported into Exposure 5 the very first time you run it. You can also re-run the import process by going to Exposure 5's preferences dialog (the ? mark at the bottom of the user interface). Then click the "Import" button at the bottom of the dialog.
If you are updating to Exposure 5 from a version prior to version 4, please refer to this article.