Select Similar Elements: Same Beat
Not only would this allow for quick velocity settings, but it would also help alleviate that weird situation of having overlapping voices cancelling out certain dynamics.
So, for instance, the user should be able to click a note"Beat 1" and in the Select Similar Elements dialogue have: All Similar "Beats" and each Beat 1 of all measures in the score would be selected (notwithstanding any other filters, like similar voice etc). This would allow again for a quick adding of dynamic marks if need be, or velocity user changes. Also, with voices overlapping in a grand-staff - the problem where for instance if voice 2 plays the same note as voice 1,voice 1's dynamic markings don't actually play but voice-2 does, but when overlapped, there's no easy way to select the notes like this and disable their "play" attribute, especially difficult for harp like notation when there's a tendency to find two voices sharing the same note.
Obviously MS has the ability to recognize which beat the note is on: it is provided in the text of the status bar. This feature would provide a major increase in functionality for the customizer of dynamics in voicing.
I'd venture to say that this is a really important suggestion and not merely an 'on the side' suggestion.