Accelerator is tied to KeyCode. When writing accelerators with number (non-keypad) shortcuts we should be using NUM0, etc.
However, in practice, these shortcuts do not actually work. But accelerators without the num do work, e.g. ctrl 0. However, they do not display correctly in the search and are not the intended behavior.
See scijava/scijava-search#34 for some examples.
My guess is there is a problem in the event framework that is not translating 0 to NUM0 when pressed?