S7, Jumping from network to another

Are the networks in STL only for purpose to make reading/writing easier(perhaps making ladder->stl automatic conversions and such easier too)? Can I jump from network to network within FC endlessly and it doesn't cause any problems, like stack overflow or something? Is there differences between other environments than S7 about this?

I feel silly to ask this after writing code for several months, but thruth is that I haven't found any other use for the whole concept of networks within function than to make code easier to read