So question, are you saying once you were upgraded to a high pressure meter and regulator, you removed the regulator from the heater side and went directly into it?

No, the regulator immediately before the heater, after the underground section of pipe, remains. That low pressure regulator exists because the heater requires low pressure. Whereas before there was one low pressure regulator before the meter and one (redundant) low pressure regulator before the heater, there is now a high pressure regulator before the meter, a low pressure regulator before the house, and the pre-existing low pressure regulator (now required and no longer redundant) before the heater. The difference is that now the pressure underground, between the meter and the heater, is high instead of low, transporting gas at a higher rate, which the new heater requires.

Can you advise what plumber you used in Houston to help with your gas line? I'm having a heck of time finding someone who will work on mine...thanks.

I live in northwest Houston and used a plumber who lives in my neighborhood, All in the Family Plumbing. If you live in a different neighborhood, you might want to look for a plumber closer to you, perhaps on Nextdoor, which is where I found mine.