I don't grow this - but I would think that being a lithophyte, it should be fine to use some rock chips - I'm not sure if you mean using nothing but rock chips, or adding some to bark mix ... If these like to remain moist, like most Cyms, you need to be sure you can meet it's water needs if potted in rock chips ...
I think when orchids are lithophytes, they aren't growing on smooth surfaced rocks, but craggy ones, so some type of craggy or porous rock material might be preferable to 'chips'.
I have my Den kingianum potted in pumice-perlite mix (more water retentive than rock chips, I imagine), and it's a bit of a pain keeping that watered in summer
If it's doing well in bark mix (roots, and all) - I'd probably lean towards staying with that. Of course, if others familiar with the species say otherwise, I would definitely go with what they say