I use symbols a LOT and find them real useful.
But I often find that I need to make tiny modifications to a symbol just for a single mockup screen.
Example: I have a dialogbox as symbol with yes/no buttons, a headline and a text field. In one of the mockups I would like to remove a button.
I can not do that . I can only edit the symbol and move things around. Makes sense, symbols are LINKS to things with local postion. Like Delphi shared forms.
Here is my idea: option to create LOCAL copies of a symbol, acting exactly like local objects that are grouped. Just like in Sketchup where you can right-click "Make UNIQUE". Now it's not a link anymore, but a local instance.
The way I solve today is create a new symbol. But it seems counter-intuitive.