When running a comparison, a user should be able to import a list of metadata items based on an agreed format (likely API names). This list would allow the user to save effort from copy pasting api names if they track their changes in an external system. For example, we track changes in our release system within our Salesforce production org. Our manifest items are tracked such as "customobjectc.customfield__c" and have statuses such as new/updated/deleted so we have a historical references of our changes. Being able to import these changes while still having the ability to select permissions/profiles/related changes would allow us to speed up the time to deploy large sets of metadata items.