>>>> But Frost was in a position to influence, engineer and reject the reception of his poetry and his vision. Why didn't he ever avail himself of the opportunity to tell his readership that he was "terrifying" ? Why had he not before strongly rejected the prevailing perception of his poetry which, if Trilling's view <i>is</i> correct, was incorrect.<<<<
Second Coming to Frost .
If a poet , painter , artist in whatever field is sure (as far as that goes) of what he brings about, why would he have to explain to his public that he is 'Terrifying'?
From the article I understand that "the Notebooks " contain many random notes and I think he certainly did not write these notes for the purpose of ugrading his image.
I can agree with you that mr. Trillings may have taken the opportunity to upgrade Frost's image calling him : "terrifying" because he had come to the conclusion that Frost was.
And the "Note books"gave him the chance to do so.
Frost being present at that moment may have thought : " Amen" and
taken his drink and made a toast in his mind to his poetry, (not his purpose or person) in private.