Making 51-100 mandatory is helpful in stocking up poms for the actual fight from 101-200. But even with that said, it is possible to raise the check point to 101, increase spawn rate of silver chest and reduce the drop rate of potsheds from 101-150. At the end of the day, I still think 51-100 is just fluff content to serve as a time gate so people doesn't burn the content as fast as they would otherwise.