I'm on 4.1.0 & my brother has an updated 5.1.0 console and I was able to update my joycons to the 5.1.0 update. I haven't seen anything like this on here confirming this is ok but I obviously didn't need to update my 4.1.0 console to use the updated joycons or anything crazy. If this has been covered fine go ahead and close this thread but I didn't see anything about it. Now I wonder if I can update my games from the updated 5.1.0 ones on my bros console as long as that update doesn't require something from 5.1.0.