Anyone stumbling upon this in the future should know that when you call the AddMappedSkeletalMesh node on ControlRigComponent, it replaces the actors Anim Class to “ControlRigAnimInstance”. Which is why it doesn’t seem to take on changes you make to your anim blueprint - It simply isn’t using the anim blueprint you have set.
I’m not sure why it is replaced or if its possible to edit the ControlRigAnimInstance at this time, but knowing that it is swapped out will hopefully prevent someone from wasting many hours like I did.