SpaceX BFR reusability simulation video

The SpaceX Mini-BFR for the Falcon 9 will only be used for testing and will not become a fully reusable second stage for the F9 or FH.

If SpaceX makes the F9 upper stage more reusable. Elon has said they will add more thermal protection to the upper stage. They will see what the least amount of mass necessary to return the upper stage in a condition that is reusable. Elon is confident reusability can be achieved. However, effort and focus is on the BFR.

New SpaceX BFR Simulation from Low Earth Orbit and Return