I think you could repot or leave it a bit longer, as you please. With the oncid types, I usually wait til they are pretty much climbing out of the pot. Is this a new acquisition? If not, and you haven't had any problems with the moss, I'd stick with it since it looks so healthy. If it is a new one, personally, I'd switch to bark bcs I am a heavy waterer...but they can dry out in bark if you aren't careful. I use a finer bark mix than I do with my catts.