You can conditionally retrieve only the changed application settings.
The client application persists its application connection settings locally when there is any change made to server settings in SAP Control Center.
http://host:port/[public/]odata/applications/{v1|latest}/Connections(‘{appcid}’)?If-None-Match=”${ETag}”
The ${ETag} part of the URL is a version identifier included in the response of the GET method. If the ETag value of the current application settings is the same as the value included in the request, a status code 304 without a response body is returned to the client to indicate there are no application settings changes.