@annasill Hmm, treating a recurrent infection without knowing what bacteria you are fighting isn't generally a "best practice." And the sputum culture is the way to do it, so it is concerning that the new ID doc doesn't order one.
Have you considered finding a MAC & Bronchiectasis center of excellence near you?
https://social.bronchandntm.org/directory/find-a-bronchiectasis-and-ntm-center