Google Docs new variables and custom building blocks

Two questions: about Google Docs new variables and custom building blocks features...

For variables, how do we make them look like normal text when its time to share the document with a client?

For custom building blocks, how do we make them available to use (and edit) for multiple members of our Workspace account? And must every block master be in a separate Google Doc (it would seem easier to manage a library of building blocks about a certain top in one big Google Doc).