Best potting mix for my oncidium roseiodes x cooksonianum

I have had an Oncidium hybrid for a long time. I potted it on into a bark, spagnum moss and perlite mix wich has worked wonderfully. Now, I want to start using more regular waterings (as in scheduled waterings so they are more consistent say every friday fpr example depending on the orchids needs of course) to my orchids and I wanted to know from any Oncidium experts out there if its a good idea to change its pot mix into just bark since I will be watering more often or does it still benefit from the spagnum moss even with the frequent waterings? It was sold to me with only bark by a specialist nursery of orchids so I am also wondering about the needs of my oncidium, its an Oncidium roseiodes x cooksonianum.

Anyways, some places it says oncidiums do fine with just bark and others say to mix with spagnum ao quite confused on what to do!