Yep, the fuel takes tighten up and stop leaking, and the titanium flight surfaces heats and warps a bit. Essentially, after it has cooled down, you have a new aircraft after every flight. Well, new or different flight characteristics than the previous flight.
Makes sense they're using the 71's fuel, and using it in the engine cooling system just like the BlackBird.
That Kelly Johnson sure was ahead of his time.
Opps. takes = tanks