TMB-
I disagree with you. For Rabbi Neustadt, a rav respected in the chareidi world to quote R. Y. H. Henkin for a source clearly indicates that he is considered reliable IN TERMS OF SOURCES. Obviously it has no bearing on how reliable he is in terms of psak. But it clearly shows that he is believed by the mainstream-right when he quotes his grandfather and he isn’t regarded as a liar.
And yes, I’ve been through his seforim, but his personal views are irrelevant to what I am trying to say here. All I am saying is that he is considered reliable when he quotes his grandfather.