Meh, instahots require 240v power or dedicated gas lines and venting. Your gas bill went down but if you used AC powered instahots your electric bill went up.
Recirculating pump only helps keep the hot waiter piping hot all the time by moving the water in the bottom of the tank and out the top to the main piping. This helps have hot water faster, without it you wait for a few seconds for the how water piping to drain out all the water sitting in it...
hot water recirculating pump, check valve and ball valves for service. A Watts automatic air vent with dual zone returns from the house.
It puts warm-ish water in the bottom so the heating element does not have to work so hard.
DOT regulations only carry weight if they are enforced. And by my observations i NEVER see anything like this enforced. Lots of sketchy shit going on the highways, those "Mexican Movers" with shit piled 12' tall and pulling "In tow" vehicles. To gringo methy tweekers with thier dumpster finds...
Well, when you are a big shit talker and always beat a drum high on the hill you will continue to reap the rewards of being a douche. He dug his own hole and people don't forget.