All plugins are external extensions which are included into theme because for each product we purchase “Extended license” and that’s why we are able to include it into them.
This plugins work fine without activation and you can always get actual version if you want directly from us.
Just ask and we’ll send you current version. We update plugins with theme updates time to time so with each next theme update, plugins will be also updated.
The option with registering of these plugins has been already added to plugin and this only allow you to get automatic updates and support for this plugin directly from author if you need.
You don’t need to register this product because it is not required but if you want to get those features, then you need to purchase this plugin directly from author. This is how it works for all themes on Themeforest and not only in our case.