in ver 1.4.5, I was able to export registrants list from frontend. Updated to 1.4.6, I cannot see the export button from the frontend for any event. In configuration, I did add the user ID in the field "Users can manage registrants from front-end"
Nothing has been changed in the extension for export function in version 1.4.6, so it should work fine (I have just checked it again and it works fine). You can submit a support ticket so that I can check the issue directly for you on your site.