I guess it depends on what you mean by moving the discussion forward.
I don't believe Feeney was a heretic, and yet I agree with Lefebvre and not Feeney.
I don't automatically jump down everyone's throat if I disagree with them. Doesn't mean Fr. Feeney was 100% right on this issue.
"The strangest feature of this case is not, as might be commonly supposed, that some Boston Catholics were
holding heresy and were being rebuked by their legitimate superiors. It is, rather, that these same Catholics
were accusing their ecclesiastical superiors and academic mentors of teaching heresy, and as thanks for
having been so solicitous were immediately suppressed by these same authorities on the score of being
intolerant and bigoted. If history takes any note of this large incident (in what is often called the most
Catholic city in the United States) it may interest historians to note that those who were punished were never
accused of holding heresy, but only of being intolerant, unbroadminded and disobedient. It is also to be
noted that the same authorities have never gone to the slightest trouble to point out wherein the accusation
made against them by the “Boston group” is unfounded. In a heresy case usually a subject is being punished
by his superior for denying a doctrine of his church. In this heresy case a subject of the Church is being
punished by his superior for professing a defined doctrine." - The Loyolas and the Cabots (PDF attached)