TRUE. The 'heart-burn' is smoke. The smoke comes from inefficient burning. It's like a campfire that is just smoldering, not burning.
The best and easiest remedy for 'heartburn' is to drink a small cup of vinegar (more acid). This will help the stomach digest(burn) the food properly (most efficient use of the energy in the food) and minimize the smoke (wasted energy).
You have it right. So many are duped with this issue just like the virus issue.