[schnautza]

I think there could be improvements in the editing environment. 
First, I'd like to see a separate button for freehand drawing and shapes like rectangles. I commonly will want to draw a white rectangle with white fill to hide something in the music and then I'll draw or stamp something over that area, but this requires many clicks that take too much rehearsal to control the freehand/box setting, line color setting, fill color setting, back and forth every time.

ANother nice feature may be to add optional white backgrounds for stamps. For example, our director tells us to change a dynamic from mf to mp...it would be great to just stamp a new 'mp' over the mf instead of needing to white out the area with a filled white box.

Mostly I'm looking to make edits as quickly as possible in a rehearsal setting to keep up with everybody else.

Ill list other suggestions on this thread as I think of them.

[sciurius]

This is the way I do it.
During rehearsal I make all changes with freehand. That's quick (three finger tap) and easy (I have an S-Pen).
Later, at home, I apply the changes to the master sources using whatever convenient tools, and upload new versions to MSPro.

[schnautza]

After a few more weeks of using this during rehearsals and in-home practicing, I've noticed a few important stamps are missing from the stamp collection.

Accent (>)
Marcatto (^)
individual note heads without stems, solid like quarter/eighth notes (I use these to add a harmony to an already existing note without worrying about the note stems matching)

It would also be ideal to see a customizable palette that you could place your "commonly used stamps" in. I'd make this be a tall vertical box that has the ability to be moved around the screen and kept open despite using other commands, such as the freehand edit.

I also would still love to see the commands for freehand lines and rectangle separated as when I'm in a hurry, I always end up with the wrong one and have to keep hitting "undo" and change my colors and fill settings every time.