I received the following very helpful answer to the question of Father Robert Taft’s two pectoral crosses (see here and scroll down to comments). It comes from a friend and former student of Father Taft.
Archbishop Stephen Sulyk, Metropolitan Archbishop of Philadelphia of the Ukrainians (now retired), elevated to the dignity of Mitred Archimandrite Father Robert F. Taft, S.J. Sulyk celebrated the elevation during Vespers on May 5, 1998, in the Chapel of St. Josaphat Ukrainian Catholic Seminary, Washington, D.C….
Let the record show that Taft didn’t see the dignity as necessary. But it is safe to say that Father Taft was persuaded to accept this honor after consulting several respected and authoritative priests and religious superiors, including Jesuit General Father Peter-Hans Kolvenbach who himself has received the equivalent dignity in the Armenian Catholic Church. Officials of the Congregation for the Oriental Churches were in favor of Father Taft acceding to this dignity. Father Taft also received a pectoral cross as a sign of esteem from the Ukrainian Orthodox Church.
As you know, the title “Archimandrite” (from the Greek, “head of the fold”) is a monastic title given to abbots of monasteries but most often given today as an honorific rank, conferred on celibate religious priests in the Byzantine Church…
What also ought to be remembered is that Bob Taft is a good model of integrating faith and reason. He lives the liturgy and is a scholar of it. He makes no changes in the liturgy but he writes about it from the historical perspective and advises the bishops on how to proceed since they are the only ones who are capable of making changes where needed.