Cert for link is bollocks.
They should but more subjective tests for that sort of stuff. Aftermarket ecu is redundant clause anyway since there is power clause (which is hard to prove) and soon to be emission clause.
Oh and how the hell they going to prove if you have chipped ECU? Somebody who wrote VIRM was reading too many ads for chips in the cars. They do not increase power that much anyway.
Take a stock car and put Link ecu, you will have hard time to squeeze power beyond standard level.
As for exhaust, if it exits behind the perimeter of passenger compartment it is not an exhaust leak.
With my car having 2 external wastegates (plumbed back into exhaust), 1x 3" straight through muffler (oval type) and 3" mandrel bent system. I do my wofs in a compliance centre, and I passed a few times (inspected by different inspectors, old and young), the car is very loud under full boost, but when it idling and normal operation it is relatively quiet (although substantially louder than stock). Although these guys do a lot of real race cars (that's where many overseas targa cars are getting NZ WOFs) and are used to diversity, and have nothing against modified cars.