Currently, each user that installs RA needs to manually set their Working Directory. If, for some reason, they decide to move their TFS Workspace (or switch workspaces, because you can have many), then the user must also modify the Working Directory field in RA. The Active Workspace information is available in the TFS API, so when the VCS for a repository is set to TFS, then RA should always set the Working Directory to the active Workspace.