just a little detail here from 3rd to 1st person …
If your animations are not setup for 1st person, they will most likely be very jittery and lose that “smooth” transition feel while in 3rd person. I have tested this with several 3rd person animation sets, to include, MOCAP animations. Just keep in mind, if they are not made for 1st person, they will have visual issues (will … might … they might …).