Kira was never a failed accord. Just untrained. Aura simply hates that he wasn’t created as one of her children. Or maybe that Ulen created someone who surpasses them.
I guess the main plot of the movie is all for the Moment that Lacus Finnaly wear a hot Fan Service battlesuit is the wing on the back has a function or is added to give the Mighty Freedom combine Scene more Fan service and when You thought Freedom can't Get more powerful now its minor weakness of having the weakest on defense of all the 3 Main Gundam is Resolved it even give it a anti barrier sword for close combat even though Kira's specialty is long range multi atk now he can now focus on atk while Lacus Focus on defense❤
Looking at the Freedom's new wing design and the way it took out all those missiles and ships it looks like the Mighty Strike Freedom has a Neutron Stampeder system built into those panels in the wings.