Hey DannyJ,
Nothing profound here, just a thought.
I wanted to mention something quick about betaine. This is not related to the HCl portion, but just the betaine. Tri-methyl-glycine (betaine) is a very strong methyl donor and taking many betaine caps could result in over-methylation especially within the context of low other b vitamins. B1, B2, B3, B6, pantothenate, and biotin, and whatever else.
It may be worthwhile experimenting going off betaine HCl and trying some apple cider vinegar caps (ACV), instead.
Something like:
http://www.iherb.com/Now-Foods-Apple-Cider-Vinegar-High-Potency-450-mg-180-Capsules/358
ACV is not as acidic as betaine HCl, but it has a decent amount of acid, and many people do well with it. But it also doesn’t have so much methylation potential! So I figured it worth an experiment.