I noticed the versions of MDC are different in MuVi vs. the library. I don't know if this means that both versions will be used in the APK (I don't think this is the case) or whether 1 of the versions will be chosen (but I don't know which). To avoid this being a consideration, could match the releases of MDC-android so there's one-to-one mapping. When you update one, you update both.
Extracted the theme playground to another repository here: https://github.com/ataulm/material-design-components-showcase
TODO: