Multiple articulations on a single note possible

I found this on the Sforzato, so I'll use it as an example.

To see this bug

Enter a note
press shift+v
press shift+v as many times as you like

Result: a Sforzato (<) is added for each shift+v pressed
Expected: Sforzato toggle on and off for each shift+v pressed.

or
Enter a note
double click the Sforzato in the Articulations palette.
Select the note (since the Sforzato is now selected) double click the Sforzato in the Aritulations palette again
Result: two sforzatos are added to the note
Expected: only one sforzato is added to the note, subsequent double clicks do nothing.

Note: the same thing happens on other articulations. In the case of staccato, the dots are stacked on top of each other. You can tell this by clicking a staccato and pressing delete and see there is another staccato there. I have only tested sforzato, marcato and staccato which all have default shortcuts.