Current State:

When using Assets External Imports or through any 3rd part add-ons Mappings are defined using API as well.

If we want to change the selector from UI or add a new one, then its not possible from UI and shows No Options.

Only way is to update the Mappings again using API.

Proposed Future State:

Provide ability to update the Mapping from UI for External Imports and from add-ons.