Project Extensibility - Custom Fields

Hello,

In the app Custom Fields and Logic I see that we can add a custom field to the Project Header and Project Element. In which apps would you edit those for each project if added?

As a test I added a custom field for Project Element and went into the Project Builder app and could not find it visible anywhere (at any level, project def or wbs element). It is my understanding the Project Builder app is the only place you can create or edit a WBS element for an Enterprise Project (Capital Investment Project in my case), what am I missing?

Also will these custom extensible fields be visible in the standard reports or do we have to create all custom reports to use them?

Thanks,

Ryan