Sounds like you either need more throw, a little higher idle speed or you are letting the plane get too slow before you try to push over. If you are flopping try starting the rudder input slightly sooner, before the plane gets too slow. Or, leave a tiny bit of throttle on at the top, sometimes a little more propwash is all you need. Just be sure that you dont wingover. I'm not talking about kicking the plane over with throttle (although that can work if you do it perfectly) I am talking about a little bit higher idle speed so that the rudder is more efective with less throw.

If the plane is wanting to pendulum on the way down, continue to hold in just a touch of rudder input on the way down, easing it out as you descend so that it does not show.

Im new to IMAC, but in pattern the track of the airplane is what matters. Doesnt matter if the nose is yawed a little to wind correct as long as the track is straight up/down. Im curious if this is the same in IMAC. I havenever really asked I just do it, it might be a downgrade. I will be interested to see what the rule is.