Sending periodic registration is OK, are you seeing the phone services switching to different subscribers under connection status page on Jabber? Regarding the number of nodes, it depends on the provisioning, are all the nodes have UDS? Or other node...

Use the second process. It should keep your certificates and associated private key file.   You can also get the private key manually if you want to play safe by loging via root and navigate to /persistent/certs folder and cope the priv-key file. Cer...