Here's the deal:
The LP dude just set a new 'pig'. There's a 10 psi at the tank, to tame line pressure that runs underground to the house.
At the house, there is a 13" (~1/2 psi~) regulator for the house appliances...so, if you wanted, you could run a 'T' from the main reg, bury a new line, say going into the garage, and coming out of the ground feed it thru a hole above the foundation, as in thru the siding/wall. Distribute this in the garage as you need, utilise a 1/2 turn ball-valve water heater type valve, and you have a large supply of 10 psi propane.
It is code-legal (at least here) and safe.
Propane companies have regulators, and copper tubing, and on the trucks that do the install, but not the 'filling' trucks.