I take the Zinc/Quercetin but normally only when I think I might have been exposed. If it helps with asthma it might be beneficial to just take it regularly.
I take one every other day, the NOW brand Quercetin with Bromelian, 800 mg Quercetin. I could probably take one a day but dang I am already taking so many supplements, by taking things every other day it works for me. IIRC if you google quercetin and asthma you will find some articles. I started with the Quercetin for covid but then my asthma cleared up dramatically. I have not used a steroid inhaler for more than 6 months. Also after taking it for covid for 6 months my doc said my lungs never sounded so clear. Best wishes!