Does it make sense to use activation keys if you are only using SUSE Manager for patching? The reason I ask is that if you create a SLES11-SP3 key, "1-SLES11-SP3" and add the child channels "SLES11-SP3-SUSE-Manager-Tools x86_64" and "SLES11-SP3-Updates for x86_64", and create a SLES11-SP4 key, "
1-SLES11-SP4" and add the child channels "SLES11-SP4-SUSE-Manager-Tools x86_64" and "SLES11-SP4-Updates for x86_64", what happens when you upgrade a system tied to the 1-SLES11-SP3 key to SLES11-SP4? It will still be tied to the old key.
If you have tens or hundreds of systems, do you then need to edit /etc/salt/minion.d/susemanager.conf on all of the updated systems and modify the activation_key variable for the correct activation key?