I see your point. I think we may have different definitions of "moderate" in the liturgical sense.
I certainly don't claim to know the state of the liturgy in the TEC in the past, but I don't necessarily see vestments as a mark of Anglo-Catholicism in the wider Anglican Communion. Have they been a controversy? In the past, yes, now, I don't really know. Certainly the use of vestments was a part of the controversy between conformists and non-conformists in the early stage of the Church of England (the Hooper-Ridley debate, etc) and even in the 1552 prayer book there are guidelines outlawing the use of the vestments other than a surplice, but the 1st prayer book rubric didn't make specify which articles of worship were allowed or not ("Here is to be noted, that such ornaments of the Church, and of the Ministers thereof, at all times of their ministration, shall be retained and be in use, as were in this Church of England, by the authority of Parliament, in the second year of King Edward VI"). And during the reign of Elizabeth I, the alb, cope, and chasuble were certainly used (and variously, as there were many protestors that refused to use the vestments) and were for the most part normative (among the Establishment) anyway. So there is certainly a historical precedent for the use of vestments in Anglicanism.
I say all that I guess to say that I don't see the use of vestments as something foreign to moderate Anglicanism. Practices such as adoration of the Blessed Sacrament (though Lancelot Andrewes spoke in favor of adoration), transubstantiation, eastward facing celebration of the Eucharist, etc. are all "Anglo-Catholics" developments. But arguably, I don't see vestments as such because they have a historical precedent in the early days of the Anglican Church.
In reality the Episcopal Church in the US has changed liturgically over the last 50 years, but I suppose I don't see vestments (and I suppose I would have to ask you what you meant by "altar trappings"...candles on the altar?) as a radical shift from the via media liturgy of historic Anglicanism, but I do see adoration, etc. as a radical shift.