this migration process converts everything 1:1 including Public ip's and once you commit there is no rollback option. During our migration process we decided it was best to simply create the Virtual network, storage accounts with encryption enabled, public ip's and so on, using either recovery services to clone the vhds to the new storage account and start them up or in some cases we shutdown the old environment and cloned the vhds.
the reasons for this was: We wanted to have the option to fail back our production environment We wanted to reduce the overall amount of public ip's We wanted to have storage account encryption enabled, data already on the current storage account is not encrypted, but by moving the vhd we insured they were. we wanted to correct naming conventions and create scale sets, application gateways and so on. we also redesigned the infrastructure during the migration process.