I’d encourage you to work on getting the post nasal drip and reflux under control as well as your asthma. It sounds like what you had been trying didn’t work for you. I’ve only been diagnosed a bit over a year, but had problems with a couple types of cough much longer.

I had a couple small nodules found by an urgent care doc 3 years ago. The f/u CT a year later was much worse with trees in bud, ground glass, etc and I was thought to have MAC and was referred to a local pulmonologist who prescribed Azelastine for the horrid episodic coughing since he thought it was PND and he found I also have mild asthma. He started Stiolta and albuterol for asthma, avoiding steroids due to possible MAC. The Azelastine for post nasal drip helped the horrid cough a lot, but the little nagging, persistent cough remained along with some hoarseness.
I went to Mayo 15 months ago, was diagnosed with bronchiectasis and cultures were negative, I started on albuterol nebs, Advair and a triple nasal spray with Ipratropium, antihistamine and steroid. The steroid inhaler and spray helped so much! The nagging cough was gone with 24 hours and after aggressive treatment by Penn ENT with nasal meds, including sinus washes with steroids , my sinuses, including persistent frontal sinus issues, are finally better controlled and my hoarseness is only intermittent now.

I tell you this because you’re following the Lung Matters protocol and there is some good info there, but just saline rinses didn’t work for my sinuses nor did avoiding steroids control my mild asthma. I’m a retired RN and knows the problems with steroids, but for me, the benefit has outweighed the risks. I posted about the meds helping my cough and sinuses there a couple times and the posts were taken down quickly since they aren’t in that protocol. People are different and one approach may not work for everyone.