I haven't been enjoying the experience of COPS too much, so I decided to recreate a texture I created using normal texturing tools. It was then that I discovered that attempting to change the point interpolation of any point in an MTLX Color Ramp or Float Ramp results in no change; it will just immediately reset to linear. I've tried both 21.0.700 and 21.0.729, I've tried inside and outside of a material builder network, and nothing. This does appear to be particular to the MTLX nodes, as any other ramp node lets me change interpolation to my heart's content. Is this a known issue? Is there a workaround?

Definitely a known limitation as the help for all MtlX or Karma ramp nodes mention only linear interpolation

I personally find MtlX standard very constraining and almost not evolving, giving me feel of being stuck 15-20 years in the past compared to modern shading solutions, especially for renderers that can't use OSL or MDL like Karma

Is there something you'd recommend instead? None of the other shading methods I've tried within Karma display in the viewport. Eventually I'll get a license for Arnold, or maybe Redshift, but for now I'm just making things work with what's in Houdini.