This is one of the most interesting puzzle metrics I've ever seen. Unfortunately, work and life stuff only gave me a few hours to devote to this puzzle. I messed around with wanding to try to extend the time the reagent spends on top of the input, but I couldn't get it to work. 

I feel like in theory, two desynced arms needing to line up could be really interesting, but I didn't bother messing around with it, I'm excited to see what people with more time/experience managed to come up with!