One frequent use case I have is to tag sets of discontiguous glyphs. In FontCreator 13 I did this by using the Transform Wizard to override ranges by glyph names or code points (the only operation in the script). After I hit OK, the required set of glyphs are selected in the editor and I can then tag them.
In FontCreator 15 if override ranges is not followed by another operation then the glyphs are not selected when I hit OK (if override ranges is followed by an operation to do something to the glyphs then they are selected on completion, but in my case I only want to select the glyphs as tagging is not supported in the transform wizard). It seems to me that this change of behaviour is a bug.
You could also consider adding tagging to the list of features in the Transform Wizard.
Andrew