> And so he claims they are compatible, but to do so he redefines free will, then claims he hasn't and that was the definition of it we were working with all along. It just isn't convincing to me.

But what makes a "definition" primal (true, non re-defined, original)? Is there such a "definition" in the first place and how to determine it? Should we make surveys accross culture? Should we analyze how "freedom" is used in practice? Should we look at historical lineage and development? Are you sure your linguistic intuitions track the "right definition"?

Sure, compatibilist free will may not match with the kind of free will you are concerned with; that's fine. You can say that's not the "free will I am concerned with", but that doesn't say anything about what's the true definition of free will is supposed to be, and what is supposed to be the "criteria" for distinguishing true definitions.

Compatibilists go as far back as Stoics and ancient. And the incompatibilist ideas of randomness-infusion is also explicated by philosophers. So it's not clear why the explication of some philosopher should be automatically privileged above others.

Personally, I don't think words really mean much of anything deep. Words are used within a pragmatic context. It can involve complex rules of play and how one person use it can subtly diverge from others. And internal intuitions can be incoherent. So neat and clean "definitions" are a lost cause. I don't think there are "definitions" out there to discover such one is "true" or "false". There's just messy usages of words to attain some pragmatic means.

Any attempt of definition is an approximation; I personally believe we should focus more on conceptual engineering (in a sense it can be "re-definition" but with a purpose -- to give more exact form to a usage and rules of usage that comply with how it's practically used and also simple)

Note that science does "conceptual engineering" too. For example, making pluto "not a planet", or defining temperature in terms of mercurial expansions, or making whales not a fish. Much of it is based on keeping some harmony with past usage, while keeping a trade off balance between simplicity of the concept, fruitfulness in a theoretical context, or practical use, among other things. There is nothing special about such "re-definitions".

From a conceptual engineering perspective, any compatibilist free will will fare far better than any any incompatibilist ones, as far as I can see.

I am a moral anti-realist (or anti-realist against anything "normative" (unless it is intelligibly conceptually re-engineered)), so the point about "moral" responsibility is also moot to me whether we get compatibilist free will or not. Responsibility assignment is a matter of pragmatic needs for intersubjective co-ordination. It just so happens that such assignment can help intervene and invest resources at critical points of "failure" so to say in certain kinds of autonomous causal systems. I think retributivist justice is meaningless and unintelligible either way.