In "Knowing Qualia: A Reply to Jackson" , Paul Churchland reiterates his claim that Frank Jackson's Knowledge Argument  equivocates on the sense of "knows about". This claim, originally made in “Reduction, Qualia, and the Direct Introspection of Brain States”, was criticized by Jackson (in "What Mary Didn't Know") as being based on an incorrect formulation of the argument. Churchland's reply finds the same equivocation in Jackson's own formulation: Jackson's concept of the totality of relevant physical knowledge is entirely propositional, while the knowledge she is supposed to lack is plausibly non-propositional, inarticulable and non-truth-valued.
I have been looking for counter-arguments to this specific claim, but they seem scarce. I have only discovered two so far: one senior thesis  and one PhD thesis , neither of which appear to have been cited. Do you know of any responses, specifically to Churchland's charge of equivocation, that are widely seen as presenting a significant challenge to it?
Churchland, Paul M. (1989). Knowing qualia: A reply to Jackson. In Yujin Nagasawa, Peter Ludlow & Daniel Stoljar (eds.), A Neurocomputational Perspective. MIT Press. pp. 163--178.
Jackson, Frank (1982). Epiphenomenal qualia. Philosophical Quarterly 32 (April):127-136.
Churchland, Paul M. (1985). Reduction, qualia and the direct introspection of brain states. Journal of Philosophy 82 (January):8-28.
Jackson, Frank (1986). What Mary didn't know. Journal of Philosophy 83 (5):291-295.
Abolafia-Rosenzweig, Noah O., "Mary’s Dilemma: A Novel Take On Jackson’s Famous Thought Experiment" (2012). CMC Senior Theses. 524.
DePoe, John Martin. "A defense of the knowledge argument." PhD (Doctor of Philosophy) thesis, University of Iowa, 2010.