Drawing Lock is a useful tool that makes your drawing safer by turning a drawing into a whole block. People can’t explode it or modify the objects of the original drawing, thus we can prevent others from modifying the drawing.
The M2LVPORT or Layout Viewport allows us to create a viewport on layout space by selecting objects from the model space and locate the viewport somewhere we’ve chosen in the layout space. By doing this, we can quickly create and setup a viewport for the current drawing.
With Symmetric Draw in GstarCAD, things got much easier. We can directly draw symmetric shapes. That is to say, when we draw the fist half, you got another half automatically drawn. No need to copy or mirror.