When I was coughing a lot while dealing with MAC, coughing during and after eating was a big problem, even causing me to choke on food at times.

By accident, I found out that doing my daily exercise routine, including a downward dog pose, greatly helped my airway clearance. I call it my "upside down" trick. Due to reflux possibility, I do this before eating or at least 2 hours afterwards.

I still have a great tendency to choke during meals, bringing on horrendous coughing fits. Lately I found bending forward from the waist & doing some huff coughs before a meal helps a lot with the problem. When I'm out, I excuse myself to the restroom and do this before we begin.

I'm not sure if it will help with post-meal coughing, but it's easy to try.
Sue