You should be testing early and often and not relying on arbitrary OS version numbers (Apple disagrees with you regarding the utility) to provide some kind of api stability or assurance.

This is why docker and other hermetically sealed packaging and languages (golang) systems work by avoiding the OS implementations which must change and update as quickly as possible.

The fact anyone would rely exclusively macOS level implementations and somehow expect them to remain stable and backwards compatible for any stretch of time blows my mind.