Currently creating a scaled drawings with dimensions in Layout is not intuitive.
To enter object dimensions, you can only enter them at the time of creation, and through typing something like “[1’,2’]” for example, without any real UI feedback.
If you try the same thing in Omnigraffle, it is super easy. You just go to Canvas properties, select the scale for the canvas, and then if you want to draw a box of a certain size, you just draw the box and then type in the dimensions into the properties window for the object. And you can change it at any time.
So the request is to simply add an Object Properties/Geometry panel that allows you to change the dimensions of any object in Layout. Something like this: