It's amazing that you disregard the most basic attack in your threat model (https://safeboot.dev/threats/): going after the TPM itself. TPMs are usually FIPS 140-2 L2: not something that's meant to be hardened against even basic hardware attacks.
IMHO the TPM should be a required piece but not the only piece of the puzzle. If I loose my laptop, I don't want the goods to be protected exclusively by a key that's trivial to recover from it (stored in something that's not a secure-element).
tl;dr; Use the TPM (and potentially other technologies like SGX) as part of your KDF to strengthen PIN/passphrase that the user provides. This breaks the asymmetry of offline attacks (attacker will always be bound by TPM/SGX-speed). Do NOT give it the only key required to decrypt your data.
IMHO the TPM should be a required piece but not the only piece of the puzzle. If I loose my laptop, I don't want the goods to be protected exclusively by a key that's trivial to recover from it (stored in something that's not a secure-element).
I've covered it in a talk I gave at 44con: https://www.youtube.com/watch?v=YZTWjLTz4AE
tl;dr; Use the TPM (and potentially other technologies like SGX) as part of your KDF to strengthen PIN/passphrase that the user provides. This breaks the asymmetry of offline attacks (attacker will always be bound by TPM/SGX-speed). Do NOT give it the only key required to decrypt your data.