While I personally do not believe that baptism has any effect whatsoever on an individual---living or otherwise---I nevertheless find baptism by proxy to be an unethical practice in principle. Those performing the baptism believe that the individual they are baptizing still exists in some form and is still in possession of free will. Thus, the practice screams to me of forced conversion.
The fact that you admit that this is a question of ethics means that there is no right or wrong answer to the question.
You are completely avoiding the possibility that this is the individual who is being baptised WANTS the baptism to occur.