Hi Bruce Reeves SRNS,
Can you see if the test code snip below acts similar or helps?
DimensionStylePtr dimStyle = DimensionStyle::GetByName(L"TestDimStyle", *dgnFile);
if(NULL == dimStyle.get())
FYI. Development is taking a closer look at this and we will try to provide a code snip or determine if any enhancements may be needed to add to the public API/SDK. I will provide any feedback as soon as I receive it.