For the setting name, how about `enable_profiling_of_docstrings`, `profile_docstrings`, `include_docstrings_in_profiling` ?

I'm not sure about making the setting profiling against individual classes, why wouldn't you want all? If profiling `docstring`s works (in the sense of finding slow before blocks etc) and provides meaningful feedback I don't see why you couldn't include it. Also how about using `described_class` for the class (which will either be a provided class or can be overridden by lets)...