> (which I guess is why you didn't use them)

You're right! (I don't think I considered the word "strong"). On further reflection, I think I chose "robust" as an evasive euphemism.

I think "robust" was applicable to the kind of communication I was referring to, in the sense in which some meetings of diplomats are described as "a robust exchange of views" (that's euphemistic too).

"Blunt" would have been less euphemistic; but it carries violent connotations that I didn't want to convey, as in "blunt instrument trauma". It's not one of the words I considered, and anyway "direct" covers it.

Thanks for your thoughtful reply.