Hello!
Looks great, as always.
If You thinking how to use it without copy of every existing animation, there could be a few tricks.
You can say in spell description that spell can enlarge only a human warriors, then use it as a baf (don't forget to chabge race to giant for spell duration and add penalties when attacking kobolds, goblins, halflings and gnomes)
Or, just make it a paladin(ranger?) only spell, like some God blessing, then You don't need to to another animations.
If You want to change a few more animations, than You can try to enlarge elven males, they looks too short, childish, it's not what we see in movies like LoTR. They should be not so massive as humans, but they have almost same height.
Also, You could make human females smaller (except fighter), as it was in vanilla Bladur's Gate 1.
Halflings could use shrinked elven animations instead of dwarven as they did now.
I have no EE yet, so don't know how it works. Do You need to overwright any existing slot for this animation to work or there is a new way to add playable animations?
Thanks.