I agree with all of the above. And have a couple other additions:

In the Edit window for any harmony there is a 'Test Chord' list of chords which do not work. It would be useful if they did.

After launching the program the selections in the 'Core MIDI (choose ports)' are those from the last time the program was used (as they should be), but they are not active until this dialog is opened and 'OK' is selected. It would be nice if this activation step was not necessary.