arm 6 7 and 9, and the regrab on lead, all limit this to 16r, so I am interested to see if anyone got lower rate. Maybe a purifier in the assembly chamber would let you avoid the hitch where the purifiers are reused. 

I am continuously surprised how hard these kinds of puzzles are if I go in expecting to hit a certain metric. And by how I fly past those goals by instead iterating on a mediocre solution.