While I'm finding no particularly reason for non other than effects, the ability to set a radius of a planet after it has been created, or do it somehow dynamical via the planet-info.plist, at LaunchFromStation or exitFromWitchspace seems to be a more OXPish and java method of doing things...
Of course it Would be a Welcome help to this solar.oxp author... .
I admit, that I have no idea how easy or hard this is... system redux could benefit from this to, instead of just having 4 fixed planet sizes and 4 fixed moon sizes. for 8 galaxies..
.