People who recommend HCl say to gradually up the dosage until you feel a slight “warmth” that tells you you’ve taken one too many. This could be anything up to 8 tablets. Then you reduce by 1-2 tablets and continue with that dose. Eventually, you should feel that this is too much and reduce by another tablet, and repeat this until you’re down to none.
I think bacterial problems, especially H. pylori, have a lot to do with GERD, so it won’t fully resolve until this is resolved. The extra acid and proper diet should help speed this up. There’s a pathogenic bacterium called Klebsiella that feeds on starch and excretes hydrogen, which is chow for H. pylori. Doctors attempt to eliminate H. pylori with antibiotics, but I think the evidence suggests it’s more like candida, in that it’s benign and even beneficial until it’s allowed to overgrow thanks to poor diet and lifestyle and/or antibiotics.