Confusing and inconsistent shortcut behavior.

I'm looking at changing the duration of the selected note I am working with, without leaving note placement mode. When I try to use the duration adjustment keyboard shortcuts, they act inconsistently.

For example, if I have just placed a note, it remains selected. Attempting to change its duration with Q or W does not work, but with Shift+Q and Shift+W it does. Outside of note placement mode, though, Q and W work the same as the shift-based shortcuts. Is there something I'm missing here? Why do these act inconsistently, and is there an easier way to adjust the duration of an already placed note without leaving note placement mode?

Thanks!