Export DDL feature is missing critical feature for us, selecting encoding for exportable objects. At the moment Toad supports encoding selection in File -> Save File/ Save As. But we need it in Create Script or Export DDL menu for exporting/ saving multiple objects.
Try this: Set Export DDL to save output to "Single file" (even if that's not what you really want). Pick a file name and set the encoding in save dialog. Then if you really want it on One File Per Schema or some other setting, change it to whatever other setting you want. It will use whatever encoding that you chose in the save file dialog.