Critellium. A mysterious substance. It's metallic and shiny, too soft to be good for structure, yet too firm to be pleasant to model with. Why anyone would make this is beyond me. 

But, nevertheless, here we are. This is an interesting molecule to put into such a small space. There's only a few ways the output can fit, and from there your choices of input location are similarly limited. The requirement for a disposal to make the machine loop correctly makes the the cabinet very cramped feeling to operate on. As a result, the input stage and assembly stage must be mostly separated from each other for each output. Decisions about where to store each given input atom have ramifications that aren't easy to foresee. I suspect that this same layout could be made faster, and an even faster layout probably exists, for any alchemist who wants to seek it.