This one's pretty neat, because the two arms have different pseudoperiods! Going 6P lets Arm 2 get a headstart, so we can run at Arm 1's period until cycle 45, when Arm 1 is finally forced to wait for Arm 2.

Side note: we know the secret that makes 17c possible (you can bond and dupe-fire on the same cycle) but we couldn't pull a working solve together. So from both of us, cheers to the heroes that figured it out!