It never occurs to me to do that because what I mostly do is never lined up - from animals and kids moving all around to different model poses. When it comes to jewelry (locked down camera, just different lighting and reflections) I even just grab what I need and move it over - it'll still be off by a pixel to a handful of pixels, and be seated in a corner of the image when its done anyway.

I just drag all elements from various images that I need over to the comp and line them up/align them however they fall.

Good tidbit - forgot about it and for this it would go faster, yes.

-Lew