Sonnb XenGallery does not use the default XenForo attachment system and therefore does not get in contact with our add-on. It also provides a switch to delete all original files with their meta data automatically which you want to enable to protect your users. This is why we do not need to remove any meta data from files upoaded with Sonnb XenGallery. You can install and use our add-on and Sonnb XenGallery together without any problems.