Meanwhile, I found out that the end-of-game screen messages (
You abandon your colony or
Victory is yours) are variables defined in the stringtabley.xml file.
<String _locID ='18071' symbol ='cStringGameOverWin'>Victory is yours!</String>
<String _locID ='18072' symbol ='cStringGameOverLoss'>You abandon your colony.</String>
<String _locID ='18169' symbol ='cStringHasResigned'>%s has resigned.</String>
<String _locID ='18170' symbol ='cStringIsDefeated'>%s has been defeated.</String>
So normally the easiest way to remove them or change them is to modify the file.
However, I wonder if there is any other way to accomplish this using triggers, RMS functions or even a victory conditions file. I tried with a scenario test to see if after a player is resigned you can modify anything about what text they see or how much line of sight they get, but it seems to be automatically controlled by the game.
Any other ideas?