My query actually relates to an instructor who has removed the no applied instrument restriction by completing an IRI course.
I always assumed that an instructor qualified to teach IR students in an airplane can also do so in an FNPT. However I came across the requirements for an STI course which include the necessity to be (or have been) an IRI in the case of an instructor interested in teaching IR students. This took me by surprise as I cannot understand why a current IRI would want to become an STI unless this qualification is needed to instruct in an FNPT! I had a look to see whether the privileges of an FI are documented to extend to an FNPT but cannot find this anywhere!