You have to be overlooking it. There has been no release of USB Loader GX without a button to manually add titles and I am using the exact same loader at the exact same rev.. Here is a picture of the theme I am currently using and the plus button I am talking about for example.
See the on screen plus button to the left? That's what you need to press. Like I previously stated based on the theme you are using it might have a different icon or it might be in a different place.