Monorepo best practices

Hi all! I am trying to clean up the environment settings for my Typescript monorepo, it’s unclear to me how best to approach this without introducing a lot of duplication. Some environment variables are shared across one or more packages; other environment variables are specific to a particular package. Should this be modeled as one project, or several? This seems like a common enough problem that someone must have come up with a solution. I would love to use Doppler, it looks great in all other respects but I need to figure this out in order for it to be a viable solution. Any ideas / input appreciated!!