I don’t understand why someone makes cold/hot backups if we can do normal backups with rman, the copy path is for me irritating. Once I can stop a database, I can mount it and backup as compressed backupset database it, if it’s a noarchivelog database. If I cannot stop a noarchivelog database, I cannot anyway do a hot backup. So either way if it’s in noarchivelog mode it has no sense to do it with os commands.
If it’s in archivelog mode, I can use again rman. Playing with hot backups and recreating controlfiles and other problems you find at restoring this database is not worth the time.