Here is my humble 2 cents worth: The need for spoilerons to harrier w/o rocking is mainly a wing design thing. Thinner wings with sharper leading edges stall quicker and at lower angles. Thats why some planes do not need spoilerons to harrier at all, like Caps and even CG Ultimates harrier well without spoilerons. The U-Can-Do type design can be a B---ch to harrier,mainly the transition to get the wings fully stalled. A Do type will harrier w/o spoilerons but you will suffer a lot of rocking until the angle of attack is high enough to fully stall the entire wing,and you must keep it above that point or back to rocking again. That fat ,blunt airfoil has advantages and some drawbacks. Adding spoilerons(and the Do needs a lot)spoils the lift by disrupting airflow on the top of the wing,the transition to fully stalled harrier is smoother,less rocking. There are different ways to get a model plane into a harrier,some simply need to slow down to just above stall and then squeeze in some elevator and its in a harrier/elevator.Aileron on this type of plane is all thats needed to handle a little rocking if there is any. You can pull to harrier at the bottom of a loop,harrier from a hover,from a rolling harrier,even snap to harrier(I havent tried but looks so awesome). The point is,you might be able to get a plane into a harrier without the transition and rocking that usually comes with it,I mostly use the spoilerons if needed.