After years of existence as a instrument manufacturer method, OIA 1678 is now an ASTM International Standard. The method should be used for samples suspected to contain sulfide, thiosulfate, thiocyanate, or sulfite. These compounds interfere with distillation methods more significantly than with ASTM D7511-09. The CFR 40 Part 136 footnote 6 says that any method that overcomes these interferences can be used. EPA approval is expected next year, however, the fact that ASTM D7511-09 overcomes these specific interferents should be enough to convince you to use this method. Or would you rather continue reporting results you know are incorrect?