I just found my answer: the IRS doesn't allow it. Sorry to create confusion.

Hi, this is from Form 1041 instructions:

Box 11, Codes C and D—Unused
Capital Loss Carryover
Upon termination of the trust or
decedent's estate, the beneficiary
succeeding to the property is allowed as
a deduction any unused capital loss
carryover under section 1212. If the
estate or trust incurs capital losses in
the final year, use the Capital Loss
Carryover Worksheet in the Instructions
for Schedule D (Form 1041) to figure the
amount of capital loss carryover to be
allocated to the beneficiary.