Editing Dynamics is Buggy.
If you double-click on a dynamics-marking (such as p), you can delete it or write something else. However:
You can't undo a deleted p back into existence. It becomes a... weird thing.
(Yes, you can undo if you leave editing mode... but not being able to undo deleting the p seems like a bug to me)
((Edit: SOMETIMES you can undo if you leave editing mode. Sometimes the dynamics just vanish.))
If you delete the p, you can write f, but it doesn't turn into an actual dynamics-f.
Are these things intentional? It seems a little pointless to give users the ability to edit dynamics if all they can do is mess things up.