Remember to restart Konnect after modifying the registry. If you want to verify that the configuration was properly loaded you have to modify log_level in /app/data/konnectd.cfg to read /app/data/konnectd.cfg. With another restart Konnect will then print a message like the following at startup:
@jdaviescoates I took a quick look at some video tutorials, but I didn't see how Keycloak would be able to log the user into other applications without having said application specifically implementing the Keycloak integration.
You've already looked into it more than me. I guess Indiehosters have implemented Keycloak integration into the apps they've integrated in their Liiibre service (perhaps they maintain forks or something, or have contributed upstream).