n0mesorah,
““It is less questionable””
“It depends what the “it” refers to. “Questionable” refers to the doubts Rav Moshe had about those eiruvin.”
Besides for Rav Moshe objection it is less questionable. Rav Moshe is mechudash, and is in opposition to most poskim (e.g. the criterion of mefulash, which case he is disagreeing with the Magen Avraham). Regarding Brooklyn he never issued a psak din barrur.