Margin and layout size don't mean anything for performance (it doesn't matter what their values are at all). Offscreen is meant by anything outside of the game's window (you can't see it while playing basically).
Offscreen may not be rendered by the GPU but they'll still have events run for them (by the CPU). Ashley hasn't done any optimization for the collision checking so doing lots of collision checks on far away objects is a bad idea.alspal2013-08-23 12:08:26
@Asit - Anything outside of the "Window Size" is considered off-screen (found in project properties). You can see a dotted line (you will only see it if your layout size is larger than your window size)
@alspal - this could be huge if there were a way to optimize collision checking for objects on screen. Frame rates in some cases could increase exponentially.
oh wait! I found a solution! Just set "objects" family when (invert)on-screen, object remove collision detection. Then, another event of set "objects" family when on-screen, object enable collision detection! It works perfectly!! I guess it was the lack of my knowledge on C2 :3