Hi,
If the device is discovered in both i.e. old and new SIM servers and reporting alerts/events to both, then swapping the IP address should not affect of monitoring.
If the devices which are discovered in new SIM does not have IP of the old SIM then it is required to make changes to those devices.
Wrt to article shared, the lines 2,3 and 4 are mean to change the configuration of SIM server with its database. If these configuration changes are not carried out, the SIM would not come up with change in IP address.
As both the SIM servers are running simultaneously and as most of the devices are discovered in new SIM, recommended to keep the new SIM as it is and discover the remaining devices. For discovering the new devices, it is required to SNMP alert destination as carried out for the devices like for the devices which are already discovered.
For the SIM certificate to push on multiple managed nodes in single task, please refer https://support.hpe.com/hpsc/doc/public/display?docId=emr_na-c03531008.
Regards,
KK