(a) Subject to subdivision (b), an administrator with the will annexed has the same authority over the decedent’s estate as an executor named in the will would have.
(b) If the will confers a discretionary power or authority on an executor that is not conferred by law and the will does not extend the power or authority to other personal representatives, the power or authority shall not be deemed to be conferred on an administrator with the will annexed, but the court in its discretion may authorize the exercise of the power or authority.