I understand the concern about reto descending into pastiche design. That said, you could say that the brick and black facade is an entirely pastiche representation of a traditional Victorian warehouse. No actual example would have the number of vertical metal clad loading bays, nor would they be as irregularly spaced almost like a bar code. Yet they are the predominant retro-design feature. In the longer term, will it become facadism or tacky pastiche?
The Leitch criss-cross pattern wasn't just an aesthetic flurry on his part. They are structural elements to strengthen the front balcony truss wall and allow for fewer supporting columns (which had been a major criticism of the earlier Park End double-decker). There could have been a genuine structural homage to Leitch elseshere, which might've avoided any criticism regarded token pastiche or retro. Some might actually see some of that in some of the truss work. Also, decorative patterns in brickwork were quite common in Victorian buildings, so perhaps it could work.