Ok Guys, Here is a situation I would like some clarification in. I am a Professional Gas piper. I have been doing it many years and for 3 years by myself.

I installed a gas system in a custom home on Mercer Island Wa, I used 2" PE pipe for 60' underground. When I came into the house I transitioned (via reducer 90) to 1-1/2" pipe to go vertical 8' into a joist bay. I then used a 1-1/2" X1" x 1-1/4" T. The 1" is for the takeoff of a boiler (155K) and Dryer (22K) That takeoff runs a total of 8' using CSST. The Boiler guy complained that I used 3/4 and it was not enough to run his boiler, Then the contractor goot spooked. I went in to reassure him the Boiler guy is being a little dramatic and the gas supply is suffecient.
The Contractor called the gas guy he has used before (i beat out for this job) and asked him his opinion. The other gas guy suggested that because I transioned the 2" to 1-1/2" before my first T that the entire supply line of 2" is now derated to 1-1/2"......... WTF? and that the "Point of supply needs to calculated from the meter not the last piece of pipe size or reduction.
I have always sized my pipe from the last reduction or T/90. Each length of pipe I install is suffecient to supply every length of pipe and appliances from that point on. But this JA is saying that the 68' of (down rated) 1-1/2" is too small to supply 572KBTU's for the whole house. I cannot get the contractor to understand that thare will be no defiency in the system. Now the JA other gas guy is going to have an "IN" to beat me out of jobs with this company. Does anyone know How I can fight this? Where can I find a picture or documentation proving my method? The Code book says "must be calculated from point of origin" and the contractor will not accept that Point of origin can be a T off of a main line. Am I wrong? I will call a local inspector but not sure I will get a live body to talk to.