I use GUI Form Editor for most of my plugin forms and often copy existing components to create similar ones.
All is good up this point, the hassle starts at re-using edited versions bundle property keys and text for the new control.
The GUI property editor forces you to go through hoops to copy the property key and value in order to use edited versions in the new control. Double that for re-using the Text and TooltipText properties.
Needing to create a new settings pane for annotator configuration and knowing that I will have a few dozen checkboxes with similar property keys, texts and tooltip texts I could not bear to do it the painful way and decided to add functionality to allow direct editing of property keys to select/create a new key without going through two additional layers of dialog boxes.
YouTrack: IDEA-208521 has a patch you can apply if you use your own intelli-community build or you can vote up the issue to show your interest in the feature.