Bulbos need to get sloppy wet every day. They have much shorter roots than other orchids. These factors need to be taken into account.
Bill Thoms wrote this:
Bulbophyllums: The Incomplete Guide
He has many awards on Bulbos.
He writes that he soaks all his Bulbos at least once a day. He is unable to water them enough on mounts to get what he considers proper growth. He prefers to grow them in low, wide baskets, with mounds of foam peanuts in the center, covered by sphagnum moss. He plants them in the moss. He stands some of these baskets in dishes of water if they dry out too rapidly.
I tried a couple of Bulbos in traditionally-sized S/H pots. They did not get enough water, declined and died, no matter how often I watered them.
I have been growing some in modified S/H in low rectangular food containers, and they are doing better. I placed a layer of LECA on the bottom, then a layer of long-fiber sphagnum moss over this. I did not put holes in the containers. I keep water in the container all the time. If I remember to water them they do well. If one dries out completely it usually dies.