I guess I stand corrected-ish. I’ve always ignored Z-Wave because it was a closed ecosystem. But upon reading more into it, seems like it’s only partially open. They only opened certain parts of the spec for interoperability in late 2016, the standard was ratified by the ITU in Dec 2019, and they formed the non-profit Z-Wave Alliance only in 2020. They apparently made the source code available end of last year, but it’s only available to the Z-Wave Alliance members.