I'm in Colorado with similar conditions. Over the past couple of months I have gradually started trying some oncids in s/h culture--just a few because I didn't know if they would like it.
It hasn't been long enough to really tell, but I am cautiously optimistic. A Sharry Baby and a Brassidium seem to be enjoying their conditions, and are putting on new growths, have lots of new roots, and have healthy looking pbs. And I really like that it's only once a week to water them--though I do keep an eye on the reservoirs. I have a bunch of paphs and phrags in s/h also, and they're loving it.
But I still have the bulk of my oncids (about 20) in clay pots with small CHC/chopped sphag/lecca media. Most of these are large plants in large pots so I am wary of all-sphag, although I do use pure sphag in my small pots. It is these smaller pots which take the several times a week watering, and that is one reason to have larger specimens and heft them around to the sink--at least it's only once a week! These oncids have different degrees of pb wrinkling--none of them severe. And they are all growing and spiking nicely. Some of these plants had pleated leaves right out of the Colorado green house which sold them to me--so I have decided not to be alarmed about that.
Like you, I have little time for multiple waterings or mistings. My plants can either get with the program or I will throw them off the deck. It's the law of the west.