I've been playing with the v4 FME Flow API for a bit and I was very happy to see the /dependencies endpoint. Unfortunately, for a workspace, it doesn't list Apps, or Automations, that that workspace is used in (which kinda makes sense, the workspace doesn't depend on the app or automation).
You can of course retrieve all dependencies for all apps and automations and check if a workspace is used there, but that seems to be a brute force / last resort approach. I would like to suggest the dependencies-checks to go both ways (so for any item list the items it depends on, but also list the items that depend on the first item)