Not entirely sure when this sneaked into the pres because i was out of the loop for a couple of weeks, but it is very recent as far as i know (Use this action quite a bit)
As you can see here the + - Semi actions don't work when hide unused unamed notes is ticked, octave still works fine though, on top of that you can see that if i go back to full piano roll view, move the note one semi, it can then be moved using the actions in hide unused unamed but only to go back to its original note hehehe.