I know the issue you're talking about regarding a polyphonic synth with a long release. The problem is a function of the pitch tracker detecting both pitches correctly, but then there is no single shift amount that will harmonize both those pitches in key. In other words, say you set the key to C Major and the shift amount to a 3rd, then you play a C and an E. The harmonizer is going to want to shift the C up to an E which is a +400 cent shift, while it's going to want to shift the E up to a G which is a +300 cent shift. Because of this discrepancy, it sometimes gets confused and can't make up it's mind, especially in situations like a synth where one note is fading out and the other is fading in. The best thing to do in this situation is switch to a nondiatonic shifter and just set the shift amount in cents. For instance, use +400 cents for a Major 3rd or +300 cents for a minor 3rd. Unfortunately, the Eclipse will actually do better than the Orville in this regard and it has slightly newer pitch tracking technology in the latest version, which the Orville does not.