I am the owner/builder of a steel building/workshop located on my property. The shop is located in NC. I was allowed after a quiz from the local electrical inspector, to wire the building.
The job consists of a 200amp Meter base, A disconnect next to it, and the 15 or so ft of conduit to get me to my 200 amp panel. I ran 2/0 x2, 1/0 for my neutral, and # 4 insulated wire for ground.
In addition to this, I had a 120 amp panel mounted to plywood, with a couple of welding circuits, and 110 receptacles, with about 100' of SO 4/4 cable that I ran to my 200 amp panel. I work in the film studios, and we often use this configuration in a large shop environment, which was my intention.

I failed my inspection today.
#1. Absolutely no temporary, or portable power panels allowed.
#2. 2/0 cable will not suffice, 3/0 must be used due to the claim by the inspector that this shop is not a residential dwelling. He told me that it is rated at 195 amps, and would be fine in the house but not the shed. According to NEC...

Obviously I will do as he asks... I have no choice in the matter.
I was made aware this afternoon by a former business associate of this gentlemen that he does not like homeowners doing there own electrical, nor does he like Yankees, which I happen to be... So is this all BS?

First of all... I'm not TK. But he's right about the 2/0 being rated at 195... but it's rated acceptable in residential service, but only as the MAIN POWER FEEDER. It's his way of interpreting the code... and he's got it nailed on interpretation. And the temporary panel? Is it not mounted to a wall or is it free standing? Not exactly sure what you have. But your 4/4 so isn't rated high enough for 120 amps. Looks like you are doing it over... in my humble opinion.

Whether the inspector does not like homeowers doing their own electric work, or Yankees, is two things to debate.

He is correct about the service entrance conductors. #2/0 is allowed for a residential dwelling only. The shed, no matter it is on land zoned for residential, is clearly not a dwelling.

You can argue the temp panel, if it can stay or not as it is part of your process. I am very familiar with stage/studio and I know this is typical, however, cord is rated less than building wire, and #4 just don't cut it for 120 amps.

Let his be a lesson to others to check and confirm an electrical design before installing.