I agree, but intersubjective ethics might not actually work in practice in a world in which people are approaching ethics from wildly different starting points. Consider an issue like abortion – people who support the legal availability of abortion, and people who oppose it, have such widely different ethical views that I think there is no intersubjectivity to be had (on that issue at least)

> Kantian ethics don't admit of an is-ought distinction (all "ought"s are in fact "is"es that are bound in actions).

I wonder, if you could expand on that point?

In my mind, Kant's categorical imperative could be viewed as either a proposed definition of the good (in which case Moore's argument is applicable), or a claim about what actually is good (in which case it escape's Moore's argument)

Kant had a lot to say about normative ethics, but the question of what his metaethical views actually were seems more disputed: https://plato.stanford.edu/entries/kant-moral/#Meta