For the 10 minutes every couple of winters that a given building will see it's peak load, 200 ft/min works just fine. Bear in mind that this is PEAK load, not steady. I've sized many system like this for 20 years, and no problems so far, and that includes a record cold winter.
Given that most people in the chain err on the side of caution - building heat loss, actual heat emitters, the convertor station, etc - by the time the steam supply is sized to meet this, you get a grossly oversized installation in which control valves hunt themselves to death, steam meters usually run far below the bottom of their accurate range, and the whole steam installation costs FAR more than it should have.
I've lost track of how many building steam supplies I've seen that have a 6" supply line that we dropped to 2" inside the building, and then to 1-1/2" for the meter.