Never as much as the drafts. Even the main characters -- and their character develops along with the plot. ("Character is plot.") Some characters don't get much, even in the final draft. An announcement of news in the royal court, during festivities, would doubtlessly have many faceless (though glittering) courtiers exclaiming in shock or glee or what have you.
Then there are those in between.
You know, if you have three superpowered individuals, two chasing a third, you can outline that section just by deciding they can all fly. But once they open their mouths, they need more. Including perhaps detailed superpowers because they need to integrate with the personality one way or another.
And when I faced my first reaction, I rejected it on the grounds that it was too close to another character I know I will introduce. (For a moment, I toyed with the eye of introducing him here, but that didn't work either.) They're not exactly foils but contrast is needed. Always.)