Unfortunately "no", because you're mixing apples and oranges.

The API650 computation for radial deflection and longitudinal rotation are based on the behavior of the tank shell. If you model that dummy rigid from the centerline to the nozzle, CAESAR II will determine the expansion (thermal strain), which is also a radial deflection. CAESAR II can't determine the longitudinal rotation because only beam elements are used.

So now you have two different radial deflection values - which one to use?

This is why if you connect the nozzle to another (2nd) element, the API650 deflection and rotation are not automatically applied.