I know how to handle galaxy forge its very simple, but if you read my first posting i want know how to change it in the _Map Designer_ and for that changing i must edit a entity file, but which is the question.
Well the easiest way to do it would be to change all HomeTerran planets to point to a different type of planet. This would effect all maps where the HomeTerran planet is used, including the map designer, but you could just turn this feature on or off with a mod.
To do that find this in the galaxysenariodef file.
planetType
designName "TerranHome"
designStringId "IDSGalaxyScenarioTypePlanetTerranHome"
orbitBodyTypeCount 1
orbitBodyType "TerranHome" #Change to the planet (defined in orbit body type section) of your choice.
You need to go to your galaxy folder in your original Sins install directory and search out the eight random galaxy files. Open them up with something like wordpad. Near the tops you will see this section:
Are you sure the Random maps have anything to do with the built in map designer?