As far as I know, all UM3(E) cores work perfectly on the S5 as well. The cores being a self contained unit have all the needed parts to work properly. I am not sure if there is a specific ruby core or not, but if so, it will solve the issue without worrying about breaking the core just trying to change the nozzle.
I have been switching between cores on both machines since I got the S5. So, it does work in my experience.