The only reason you wouldn't have dual sets of controls is to increase passenger capacity. I have flown BH206s and BH212s which had the copilot's cyclic and collective removed to maximize the # of paxs, but a mechanic could reinstall them quite easily. I have seen throw over cyclic set ups, like the R22, but I've haven't seen a set up where the sic had a cyclic only. Doesn't mean that it does not exist, but just does not make any sense. Kinda like the sic on a fixed wing having access only to the rudder pedals and not the yoke.