I see that the vercel dashboard uses https://vercel.com/api/v9/projects/:projectIdOrName/branch when the production Git branch is updated in the settings.

But this endpoint doesn't seem to be documented in the REST API docs. Is this endpoint a long-term supported endpoint that we can use? Currently there is no way to update the prod git branch using just the publicly document apis

Same for the gitComments field in the PATCH endpoint for a project. this is field is not documented too.