F5 LTM and GTM Migration from Hardware to vCMP Guest

Hello,

I have a few questions in regards to the decision being made to move the LTM and GTM hardware platform to VCMP based platform. We are in the process of understanding the procedure to do the same and therefore need some help from you all guys. I have searched some of the Q&A and got some pretty good idea of the migration, however would need want to understand a new more things. Please answer my question if you have done a similar migration in the past.

Three data centers, each has a pair of LTMs in HA and a pair of GTMs in standalone mode. All the six GTMs and LTMs are in iQuery full mesh. All the GTMs are already upgraded to vCMP guests. New LTM and GTM guests are already provisioned with a newer Management IPs, Self-IPs, and Listener IPs. Based on my understanding from various article, here is what supposed to be done.

Configure the new LTM devices with the new management and Self-IPs (and leave them shutdown), install device certificates etc. Add the new LTM device1 in config-sync with the existing HA pair of LTM devices and get all the configuration from the existing production system. Add LTM device2 in HA mode with LTM device1 and sync the config. This way the newer devices will have the same exact configuration as that of production devices. We will later shutdown the interfaces on the existing hardware platform and enable the interfaces of the newer devices. How efficient is this process?

Question 1: When the migration is complete from the older to newer systems, how would the GTMs update their wide-IPs with the Virtual Servers path pointing to newer devices?