I really miss a Select All option that actually selects the objects. It's just not possible to zoom out and select all objects and then Change Symbol, that option is not valid if I selects an area with the mouse.
The 'Select All Unmapped objects' is also very convenient. The use case is when I import a DXF file with Contour objects. Then I could select all imported objects which is not mapped yeat, and the re-map all to Cotour objects
Another use case is :
If I import a DXF file, and re-map most objects to the correct symbol, it would be easy to select unmapped objects, and the remove them.