If I check final on the K-1, the passive loss frees up but creates a large NOL.  Is this correct?

No. It has not been disposed of in a fully taxable transaction.

Should 2020 be reported under the SSN or the trust id?  Both. there should be 2 K-1s. One to the decedent for his share up until death. One for the estate.

Date of death value becomes initial basis to the estate.