The first 12 exotic metalloids are buffered become the iron and silver, then the metalloids are pulled every 2 cycles to become copper and perform the remaining projections. The fires are pulled in the same 12+12 to match the schedule of the metals. The +1 latency is mainly caused by the regrab on the left-most triarm. In theory using the last inputs for the iron instead of copper gives a spare latency to work with, but the geometry is much harder since it needs to be swung from the opposite side from where the projection is happening.
This started as a failed layout for 53, which caused a lot of decisions that are suboptimal for area. I think 54 could get away without buffering, which would save a lot of the area spent storing and transporting molecules.