Consider the following use case for the external workspace manager plugin: all the nodes have the same mounts as the master node (e.g. in a homogeneous network).
Currently, the 'exws' step looks for the disk definitions in the External Workspace Template (from global config) and the fallbacks to the Node configuration. For this use case, it may be useful to have a second fallback condition: External Workspace Definitions (global config).
So the search order would be: template, node, global.

See the discussions on https://github.com/jenkinsci/external-workspace-manager-plugin/pull/6