I'm not able to add chord notes in Denemo using the Alt+{note} keyboard shortcut (current repo version + Ubuntu Linux). Pressing some key combinations gives an error message (e.g., "Alt-A is not a shortcut"); pressing Alt+F gives me the File dropdown menu.
Also, it would be nice if, after using the Check Note Pitches feature, the dialog reading "Finished" would be given focus, so that I can hit Enter to dismiss it rather than switch to the mouse. (I haven't tested this one using the latest version of Denemo, BTW.) Wade