(a) If property includable in an estate does not come into possession of a representative obligated to pay the estate tax, the representative shall:
(1) recover from each person interested in the estate the amount of the estate tax apportioned to the person under this subchapter; or
(2) assign to persons affected by the tax obligation the representative's right of recovery.
(b) The obligation to recover a tax under Subsection (a) does not apply if:
(1) the duty is waived by the parties affected by the tax obligation or by the instrument under which the representative derives powers; or
(2) in the reasonable judgment of the representative, proceeding to recover the tax is not cost-effective.