The idea behind "Force all" is that is QueueMetrics knows you are logged on to queues A and B, but you should log off from A B and C, it will only try logging you off from A and C and will skip B (in order to save time and resources on the server). Sometimes this is not what you want, e.g. if the set of queues is incorrect, so you can use "force all" to have QM log off from all queues no matter if it is aware you're logged in or not.