Well… as long as the degree of softness is constant, you can apply that across all of the shots in the Keyframe Clip mode, you can increase softness with one overall adjustment. Otherwise, there are control surfaces that will let you jump to the next keyframe and manually adjust softness as required. If there’s dozens or hundreds of keyframes, then you have a real problem.
I’m a fan of the “divide and conquer” method of manual keyframing, where I’ll set a start point, an endpoint, then jump to the middle, and then slowly go through the scene in small increments and see where I really need to drop in another keyframe to work effectively. I also find that the Highlight mode will show you very quickly when the edge is peeking out around or over the subject.
Also, multiple shapes is often the best way to mask out people, particular heads, bodies, arms and hands. (And I tip my hat to Dan Moran of MixingLight.com for this idea some years back.)