The mantra and karma CPU support VEX, but the karma XPU only supports MaterialX. I suspect that adding OSL support for XPU would be much more challenging than for CPU, but it doesn’t seem entirely impossible—I’ve noticed that Redshift and RenderMan 27 actually support it. So, I’m hoping someone can explain whether implementing OSL on XPU is indeed more difficult than on CPU, and what the specific technical challenges are. Of course, Karma offers more powerful compernics to work with, but for some models, having to unwrap UVs and generate large textures is quite a hassle!