All model traffic leaves through one module, and which provider that module is pointed at is set where the product runs, not in this interface. A picker here would suggest a workspace can send its prompts somewhere else than the deployment does, which is not how any of it is wired.

Bringing your own key, per workspace, is the version of this that would be real. It needs a key in the vault and a per-workspace provider on the egress module, and neither exists yet.