It has been awhile since I replaced hardware on open platform and central managed licenses. I am unsure of how to deal with upgrading the hardware for a gateways. I am also planning to upgrade the software to a major version (r81.20) fresh to take advantage of r81.20's enhancements during install (disk partition alignment, etc). I have read that 81.20 has to be installed from ISO/USB to get those enhancements.
The part I am having trouble recalling is the gateway object in the management and the license for it. Since this is centrally managed and I want to use the same firewall objects in Smart Dashboard, Do I have to remove the license from the old hardware using smart update/smart dashboard before shutting down the old gateway and then attach the license after re-establishing SIC with the new hardware or can I just manually export and import the license into the new hardware so that once SIC is established, the license will already be there and Smart Dashboard would be none the wiser. It will be the same IP address for the gateway so the management would think it is the same system. This way the old license is still on the old hardware in case I need to swap the hardware back in case of major problems.
Since this is central licensing, I can attach and detach the license as needed to different gateways. I just haven't seen much about dealing with the central license with open platform when upgrading the hardware.
I am pretty sure the interface names will change with the new hardware but the core count will be the same. This is a clustered (HA) gateway.