It seems that if someone uses as much as a single independent component from your library, they will be forced to include the whole Material-UI. Whereas if you use Material UI without any wrappers, in its raw form, the not imported components should not be included in the build. I may be wrong though - I've never dealt with much of cljsjs. Have you checked whether the whole Material UI included or not when you use e.g. just a button?