I rebuilt the crashed model. Added a servo system to release rubber bands that prevent the props from windmilling on boost (suspected cause of boost #2's crash). Added a better GPS receiver, mini M8N. It boosted NICELY, and at burnout I pressed a button to make the servo release the rubber bands. Just after apogee, Throw Mode stabilized the model in an upright hover. The GPS and compass worked to provide a solid Loiter ability, and also Return To Home / Return To Launch.