I take your comment to mean that all truth-claims are “theory-impregnated.” This is sometimes known as the Duhem-Quine hypothesis, and is generally accepted by philosophers of science. Einstein himself also noted that theory shapes observation as much as the opposite.

I agree with all that. But I don’t think it undercuts my thesis. On the contrary, the first things to be targeted in any debate ought to be any unexamined assumptions.