Morph path or mask - bad line quality

Hello all,

I am attempting to morph two shapes, however, I am having trouble with bad line quality. I have tried morphing them as paths and as masks (using mask interpolation), yet, both attempts give me bad quality lines during the morphing process. Please see images. The "Start" and "End" look quite similar but I can assure you they are not the same shape, therefore, simply shifting the position and scale will not work. I am assuming it has to do with the vertices? Any ideas on how to make this transition much cleaner / smoother?

Thanks in advance,

H