Both doctors are right in that threadlifts are safer in general. However threads have their limitations when it comes to adding volume and height, as well as to contour the nose accurately (e.g. nose humps or dents). In those scenarios, a filler would be more useful.
I would suggest finding a doctor who is comfortable with both to assess your request and offer individualized advice. Aesthetic medicine is very personalized and solutions and costs depend on each individual's concern.
