One of the main challenges is the single object that appears in the current SmartConsole representing the SMS & SG.
In the distributed deployment they are separate and appear separately in the relevant rules/policy configuration. For example the VPN that you've highlighted.
You can do an export of objects easily in the Object Explorer and use that for the new build configuration.
You can also use the API for that and policy configuration.
You could inject a lot of the objects and rules into the new build quite easily with the API but I imagine there will be some manual work around some configuration, again its about the VPN (shared secrets?) and also configuration in global properties and manage & settings.
Someone will need to spend time planning, testing, and preparing before the cut over.
I'll share an API command here later to show objects on the old and prepare for important to the new.
Regards,
Don