You can conditionally retrieve only the changed settings.
http://domain: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.