200ppm sounds really high to me. Maybe not for commercial wines, but far more than I use for my own.
FWIW, I just weighed a few 1/4 tsp of K-meta and the average was 1.95 grams. Using Fermcalc with an initial SO2 of 0, 1.95 grams of K-meta and 6 gallons it took the SO2 to above 50 ppm. If one were to use the 1/4 tsp method and bulk aged for a year using every three months of racking and sulfiting it would be over 200 unless something changes when it becomes bound. This does not take into consideration pre ferment additions or that given off by fermentation itself. Again I'm not sure about what happens when it becomes bound.