This is two arms doing a 7 cycle loop, except when extra work is required. To improve I would approximately need either 3 arms on a 4 cycle loop (couldn't find, seems unreasonable), or 4 arms on a 3 cycle loop (impossible since beyond pull rate limit), or 2 arms on a <7 cycle loop or on 7 but with less extra work.

The last possibility seems most reasonable, so I would be surprised if the best solves have more than two arms. I could be wrong though.