Global (R) config file (or alternative) on RStudio Connect

I'm interested in solutions for sharing settings across all RStudio Connect content. I'm using a global configuration file (and R package config) to manage API keys, database credentials, etc.

Some other approaches I'm aware of is the "make everything environment variables", "store everything you need in each project", "set manually in each piece of content through RSConnect GUI", or "use something like AzureKeyVault".

I'd love to hear what solutions others use, and what they think the trade-offs are.