pirate ships now flee when shields are at 50% to reflect their raiding style
legendary pirates now only appear if Disaster events are enabled (Start New Game - Victory Conditions step) AND pirate prevalence is not "None" (Start New Game - The Galaxy step)
SilverMist creature now only appears if Disaster events are enabled (Start New Game - Victory Conditions step) AND space creature prevalence is not "None" (Start New Game - The Galaxy step)
.....apparently you have to disable all space creatures to disable silvermist if you still want pirates