I haven't tried anything OAuth related with Wekan, so I don't really know. Generally once we publish a package without cloudron user management, we will just take whatever Wekan is providing for settings, hopefully a GUI then.
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: