To be honest, the solution here is different. Just allow for signed firmware that uses the TPM without a time-lock. Similar things could be done for many forms

To be honest, the solution here is different. Just allow for signed firmware that uses the TPM without a time-lock. Similar things could be done for many forms of encryption at rest secured by a TPM based on a PIN or fingerprints. (Though I am not sure about fingerprints). This can essentially be done without key escrow. Though you could see this as key escrow where the signing key for code that accesses the TPM as the master key.