If you have a lumpy/dumpy/bumpy case after resizing, then you are doing something wrong!
No amount of after bullet seating crimping/sizing/fiddlying will correct bad case prep.
Setting aside the wasp-waisted result that is lumpy but generally considered desirable, sometimes a FCD's post-sizing function will iron out a small irregularity that came from a bullet that started crooked and then got straightened. A small bulge in the brass can persist. Nothing to do with case prep.