Can a white stole be used at the baptism and/or confirmation of a child or adult as the white garment called for in the Rite?

No. The traditional vesture of the newly baptized/confirmed is the white robe (alb). The stole is the proper vestment for an ordained minister…priest, deacon. “The distinction between the universal priesthood of all the baptized and the ministerial priesthood of the ordained is blurred when the distinctive garb of ordained ministers is used at (Baptism), Confirmation. “ [BCL Newsletter, Dec. 1984]