Hi i asked it in the Joomla forum and they answer :
*Welcome to Joomla forum!
The email cloaking plugin is a Content Plugin. That means that the plugin is triggered by events that start with "onContent", see: https://docs.joomla.org/Plugin/Events/Content
You can use the email cloaking plugin in non-core components or modules when those also trigger those events.
If those non-core extensions don't listen to the Content Plugin events, then you cannot use Content Plugins. Some 3rd party extensions have their own events. A programmer can program a plugin that listens to such events.
Finally, System Plugins are always triggered, so if the 3rd party extensions don't have any events, then you might be able to solve it with a custom System Plugin.*
Do you plan to solve this for Helix and the SpPageBuilder?