At work we implemented a configuration server off of a GitHub repo. No credentials, no base URLs, but that is where everything is; even the local and common properties.
The argument for putting everything on GitHub is that it should be the same in local as on Prod and that forcing the developers to check their work by pointing to their PR branch manually (add the URL to bootstrap.yml because it won’t run locally) they will commit to.
The argument against is that you will never have it being totally equal; PCF provides most of the environment/service properties that’s hard coded in the local properties… Even still, are the extra steps going to prevent a developer from not checking his work? You’re not going to prevent someone from forgetting to add the same properties over, let alone copy the properties back locally to get around your rule. Clearly I am against it, but it just looks like making code inflexible to prevent less terrible mistakes.