I do have an adjustable regulator hooked up to a quick connect that I use for my crawfish burner that I'm planning on using. I will use pipe to get the burner connected to the smoke house wall with a bulkhead fitting and a quick connect. That way I can just unplug my bottle right from the outside and it's solid pipe inside
When I build the next one. I will hard line it as well. I started with a high pressure regulator, then moved to an adjustable regulator, then my father in law needed a high pressure regulator because he bought the wrong one. So we swapped. I do also have a needle valve witin my lines.