"You model for why he speaks of eyewitnesses requires him to know of
such a means, at least."
It is clear he is recounting an urban legend. You can repeat the same dictums as often as you like - they remain baseless.
And Kira saw phased vapors - as in, no information as to how the breen look like.
"You have contested mind-changing as a valid explanation for what we see"
Have you even read my last post?
Point to where I contested that the writers changed their minds, Timo - as opposed to using straw-men and being intentionally dense with regards to you repeating dictums that have no base in what is said on-screen.
"The Breen can't be simultaneously mysterious and known."
The breen - in their latest iteration- were never known. Only rumors of dubious authenticity were known.