Shotgun toolkit relocatable Core via core_api.yml?

We recently experimented with moving the SGTK Core API modules to a location outside our config by editing the {config}/core/core_api.yml and converting the descriptor to a path type locator:

location:
  name: tk-core
  type: path
  version: v0.20.1
  path: /software/shotgun/core/v0.20.1

Seems that doesn’t really work and our apps and engines are still picking up the core installed relative to the config path. This kind of explains why core is unique and never installed to a versioned directory (unlike apps, engines, and frameworks). It does kind of beg the question why this yml file is even used/needed in the first place? Is it only relevant for distributed configs to specify the download location of descriptors of type app, shotgun, or git?