If you are using a Bundle that contains a Management and a Gateway License and is for Open Server then absolutely no need to Split the license.
If you look in SmartUpdate then will see two parts.
1 for Management and 1 for Gateway both currently attached to your Standalone Box.
Simply use Central Licensing and use the IP of the Management Server.
Build your Dedicated Management Server and then import the License into the System.
Attach the Management Part to the Management Server then Attach the Gateway part to your Gateway Box once established SIC.
When you have a Gateway License whether OpenServer or an Appliance then part of that goes on the Management Server and Part on the Gateway.
See absolutely no need to Split the license here.