I agree with cwal. If it's been a year since a culture, it's probably a good idea to get one. If you ask for order via MyChart or a phone call now, the result could be back before your appt and you and doc could discuss a plan if it's positive or be reassured if not. Just a thought. I always like as much info as possible at appt so that my questions can be addressed.
I'd encourage trying 7%. It made me cough at first, but I took it slow, sipped water and adapted.

Dr McShane's video on clearance:
https://m.youtube.com/watch

@picartist, keep in mind that it takes 42 days to culture a sputum sample for MAC and that it is common to take three samples over three days, so you probably wouldn't get any results back for quite a while after your September doctor visit. Of course, by that time, your doctor may have more information about Brinsupri (brensocatib), the new drug just out this week. I hope you continue to feel good.