If you keep the location of the rigid Remote Force at the full length of the beam and scope it to a cut face half way along the length, that will reproduce the deformation and stress of the first half. However the deformation of the remote point would be incorrect compared with the full length beam because the second half, which was flexible and contributing to the tip deformation, has been replaced with a rigid element.
So if you don't care about tip displacement and are only focused on stress in the first half, you can use a Remote Force. But if you need both the stress in the first half and the tip deformation to be correct, then you can't use a remote force. Stiffness is Tip Force/Tip Deformation so that requires the full model.
Plus... remote points update their location when large deflection is turned on.