I agree with Georges feedback… We are currently opening a West Coast location and had the same intentions. Now, I currently own locations in PA…moreover in Pittsburgh.
BOTH have the same rules…if you are buying an existing restaurant that has an already build oven you will probably work on a grandfather clause.
BUT…one thing that George failed to bring up is your insurance company who WILL send in an inspector every year as part of the policy update.
I know you feel confident that building this will not be a problem, however based on my latest research I would lay my bets on the fact that you will invest all the money in a non-regulated oven and something will bite you in the ass and you won’t be able to reverse engineer the install and will be out the money.
You may know someone in town that may rubber-stamp this…but remember, this person is only one of many and there is always one with a bug up their ass to impress someone futher up the ladder.
Think long and hard about your plan of action before you execute.