Not really, you can use the outside as a temp work area to arrange, edit or scale. Remember the real estate in the UV editor box is precious as far as resolution goes (the UVs should be positioned to fit within the 0 to 1 UV range)
The larger a piece gets, the more resolution it gets (it’s getting a bigger piece of the texture or material). Remember you can scale the UV’s separately from each other within the UV box. If you had a helicopter you were unwrapping, you’d want to think about the parts of the model the player is going to see most of… from the outside of the helicopter, particularly if he’s standing next to it. This would be the fuselage. So you’d want the fuselage taking up all the width of the UV box.
The rotor blades and couplings could be scaled down to create more space since they are above the player and don’t require the detail. If the helo is flying they are usually replaced by a blurred animation. Some parts like the inner parts of the intakes can be scaled down even more just to show the colour… (no one is going inside the intake to see the inner part details)
So, not everything has to be unwrapped at the same scale which is what happens with one-click unwrapping unless you go in after and change it.