This is not a question but more a feedback.
I'm using ADI within my intranet organization wordpress website and it works really well. However, I just have one litte recommendation. The class BulkSyncBackADIntegrationPlugin is declared within syncback.php file, but I think it would be better to move it into a new file.
Due to this choice, I'm facing a really small but ennoying issue. I'm automatically updating AD attributes when clients update their profil information (it's a fully mindful choice) to do so, I hooked a filter function to get_edit_user_link which calls BulkSyncBackADIntegrationPlugin->bulksyncback($userid) when editing an AD user. As I had to include syncback.php, I had to avoid unwanted instructions from being executed. That could be simplified by moving the class BulkSyncBackADIntegrationPlugin into a new file and we wouldn't have to reapply modifications each time their is an update.
Kind regards :)