You're preaching to the choir. We've ended up essentially monitoring responses for unknown fields / values, and periodically doing a kind of diff-ing on the documentation to see if something's changed. (This is a pain since due to "features" in CH API and the documentation we also need to keep note of "known issues" and our patches...) Updates to enum constants do tend to get announced on the forum however.
Plans to version the API (for each resource!) via mime types / content negotiation were mooted in 2015, see:
Then there was the idea of an update system for the enumeration constants. The developer documentation states ("enumuration" is theirs):
A planned enhancement to the enumuration scheme is the provision of API endpoints that will return the enumuration class catalogue. This avoids having enumurations hard-coded within a client, and by periodically checking for change through ETags, avoids clients having to download the full catalogue unnecessarily.
Looks like this stalled around 2015:
Various folks have thoughts about how it should be / could be:
There have been plans to "stream" various parts of CH now available as data dumps, if at all. These include PSCs, I can't see whether officers were to appear also but that would be logical.
Streaming of PSCs seem to have stalled in 2017, see: