We are flying with no mix at all. Two key thing come to mind... actually three. The motor thrust must be at zero measured. No down and no right. the aileron linkages typically have a minute amount of slop so i set mine up to be straight while laying the airplane on its side. There should be equal amounts of up and down deflection (slop) while in this state. Third and most important is to have good aircraft balance while hanging from the prop. If you will hang the airplane from the prop-shaft with a string and use a door frame or corner wall line... (anything that is very true to verticle) using this sight-line make sure that your equipment positioning and placement will create a situation that allows the fuselage to hang straight up and down or Plumb as it were. If set up this way and Thrust, balance and aileron droop are at zero, the plane will actually torque roll as many as 3 to 5 revs without corrections and knife edge loops are a snap. Flying thru knife edge loops is much different than 3d knife edge loops because of the torque effect while doing violent 3d knife edge walls and loops.