How faithfully does Herbert Blumer's formalized "symbolic interactionism" (1937 onward) represent George Herbert Mead's own thinking, given that Mead's own texts are themselves posthumous compilations of student lecture notes rather than a work Mead approved?

Mead never used the term "symbolic interactionism" and published no systematic statement of the theory in his lifetime; Mind, Self, and Society (1934) was assembled by his students from lecture notes after his death, and Blumer built and named the formal theory decades later, working from that posthumously edited material rather than a text Mead himself finalized, leaving open how much of "Meadian" theory is Mead's own view versus his editors' and Blumer's synthesis.