The full list of available options of Dock
Apple does not publish this and it’s considered the equivalent of a private API for developers. When Apple wants to test a new feature, they first expose it with hidden switches and then after it’s been tested and doesn’t cause issues, then it may become an official setting. Until it’s publicly documented, these change from build to build and sometimes can cause things to not work.

The only listing of these is by people who disassemble the code and then publish their work. You’re not missing any resource here, as this is undocumented and doesn’t always stay stable, so the effort to document these is quite high from a labor perspective.