I’m saying FCP crop-feather is limited because it has a very limited range of how far it can feather the edge. I attached a picture of a color matte feathered as for as it can go with the crop-feather slider. If you type in a number beyond 100 it doesn’t make a difference. Where as Motion range goes as far as you need it to.

As for doing multiple images. As Ben said, you can feather a mask on the group…or if you want each image to have a separate masked feather because you can just copy and paste the masked feather onto every image.
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