Previous revisions included bi-arms, which made the machine pretty snappy. But then I found some layouts that would use fewer instructions, if there weren't incoming product that I needed to dodge. Getting rid of the bi-arms lets me slow it down and get to 19 instructions...
And now, in addition to removing the bi-arms, I've extended it to period 7, which lets me get the timing right on arm 6, for 18 instructions. Woe, the alchemist's folly. We tolerate so much for a single instruction shave.