Hey there !
thanks to blackhornet awesome plugin I have made a very nice camera movement that bounds to areas ! you can check it in this video : youtube.com/watch
Here are the expressions I use to make that ("Masterlayer" is the name of my main layer) :
When the character goes IN the area :
inset left : lerp(ViewportLeft("Masterlayer"),area.BBoxLeft-256,dt*3)
inset right : lerp(LayoutWidth-ViewportRight("Masterlayer"),LayoutWidth-area.BBoxRight-256,dt*3)
When the character goes OUT the area :
inset left : lerp(Camera.ScrollToPlus.InsetLeft,MASTER.X-(WindowWidth/2),dt*3)
inset right : lerp(Camera.ScrollToPlus.InsetRight,LayoutWidth-(MASTER.X+(WindowWidth/2)),dt*3)